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Technology encyclopedia

Begriffe, Bilder und ausführliche Erklärungen zum Thema Simson & MZ alphabetisch aufbereitet

ABE

The general operating permit for series vehicles is issued by the Kraftfahrt - Bundesamt (KBA) if the vehicle complies with the current technical regulations of the Road Traffic Licensing Regulations (StVZO). The general operating permit is national law and is only valid in Germany. It is gradually being replaced by European type approvals (ETG). The type approval expires if technical modifications are made to the vehicle, unless parts are used which have their own type approval or ETG and the correct installation has been checked by an authorised expert of a testing organisation. The result of the test must be entered in the vehicle documents.

Anyone who moves a vehicle with an expired operating licence on public roads commits an administrative offence which is punishable by a fine and points in Flensburg. In addition, the insurance cover also expires with the operating permit. If the vehicle is listed in the ABE, the part can be installed. Observe conditions! For example, a technically permissible wheel/tyre combination may also require a speedometer adjustment or similar. The ABE states whether a modification approval is required for the part in spite of the ABE. Without such conditions it is sufficient to carry the ABE.
ABE

ABG - General design approval

Is a test mark assigned by the KBA. This consists of a wavy line of three periods, one or two code letters, a number and an additional character if required.

distance gauge

In terms of function and use, distance gauges are comparable to feeler gauges and are therefore usually mentioned in the same breath. >> see term feeler gauge << Common for maintenance work on Simsonmopeds or MZ two-wheelers is also the term precision valve gauge for this measuring instrument. The conical blades (either individually with 0.4 mm, in the 12-piece set from 0.05 mm to 0.6 mm or in the 20-piece set from 0.05 mm to 1 mm) are mostly made of hardened spring steel and are therefore somewhat more robust. A protective cover or the storage in the tool bag as well as a careful handling should not be renounced nevertheless.

output shaft

The output shaft is responsible for tapping the torque generated at the gearbox. It is also known as the output shaft or pinion shaft under screwdrivers. The output shaft is sealed off from the engine block by a Simmerring, which is part of the gearbox and is available for the 3-speed Simson S50, KR51/1 (Schwalbe) and Star SR4-2 models, among others, as well as with twelve bores for the 4-speed Simson S51, S70 and SR50 mopeds. With the MZ motorcycles ETZ 250, 251 and 301 as well as TS 250 and 250/1 you can even draw from the remaining GDR stock. When changing the output shaft, you should not only consider the accuracy of fit, but also the necessary accessories. These include, for example, the ball sets, spacer washer and shift fork, the sealing caps, springs and retaining rings.

exhaust

Exhaust is the designation for the exhaust system of an internal combustion engine installed in a motor vehicle. In addition to the discharge of exhaust gases, the exhaust also fulfils another important function - it dampens the pressure surges generated during combustion and thus reduces the noise emission of the two-wheeler.
When servicing and maintaining exhaust systems for two-wheelers, particular care must be taken to ensure that the exhaust and the components attached to it (in particular the heat protection) are securely seated. Because of their exposed location, the exhaust systems of two-wheelers can be more easily damaged than those of other motor vehicles. In addition, two-wheel exhausts - also for Simson and MZ - are often chrome-plated. Chrome is a weather-sensitive material, so that chrome-plated components can be more easily damaged during continuous operation of the two-wheeler than unchrome-plated parts, especially through contact with road salt in winter. In order to avoid corrosion, chrome-plated two-wheeler exhaust systems should therefore be cleaned regularly with special chrome cleaning agents.
exhaust

battery

The battery plays a rather minor role in most Simson and MZ models. Since all models are equipped with a kick starter, it only has to ensure the supply of the corresponding loads for the short time between switching on the ignition and starting the engine. From engine start, the alternator or charging coil takes over this function. Only if all consumers are switched on at the same time, the battery is loaded again, since the power of the alternator / charging coil is then partly no longer sufficient. Nearly all models from the GDR production can be driven at least without battery. The Simson Moppeds and also the AWO's can even compete. With the MZ's must be pushed without battery. In the GDR lead-acid batteries were used in general. Lead was, and still is, an expensive commodity. With the Simson models S 50 N and S 51 N, the inventors have shown that a moped can also run without a battery. Only to support the horn, a dry battery was installed.
battery

gasoline hose

The fuel hose connects the fuel tank and carburettor on motorised two-wheelers. Both the fuel tank (or more precisely the fuel tap) and the carburettor have hose connections to which the fuel hose can be connected. The external diameter of the hose connection - which varies depending on the type of vehicle - is decisive for how large the internal diameter of the petrol hose may be. Fuel hoses for motorised two-wheelers are made of different plastics. To prevent the engine from "stuttering", a proper fuel hose is essential. In order to filter out tiny particles from the petrol before they can reach the engine, most Simson mopeds and MZ motorcycles have an integrated petrol filter at the petrol tap (i.e. at the exit of the petrol tank). In addition, further filters can be inserted into the fuel hose. However, it should be noted that on some models (e.g. the Simson Schwalbe) the gradient between the fuel tank and the carburettor is very small, so that the installation of additional filters can hamper the flow of petrol.
At regular intervals, the fuel hose of Simson mopeds and MZ motorcycles should be checked for leaks and a tight connection to the hose connection.
gasoline hose

Bilux lamp

The Bilux lamp, originally a brand name from Osram, is a so-called two-filament incandescent lamp, consisting of a dipped-beam bulb, a shielding pan, a high-beam bulb, a glass bulb, a guide disk, a bulb base and connection contacts. They are used, for example, for long-distance and dipped-beam lighting. The Bilux lamp is picked up by the reflector - a component of the headlamp insert. Depending
on the vehicle model, it has a voltage of 6 volts or 12 volts and an optional output of 15 / 15 watts, 25 / 25 watts, 35 / 35 watts or 45 / 40 watts. Also depending on the vehicle is of course the choice of the right base. ATTENTION: Some Bilux lamps are not valid in the area of the StVZO.

flasher unit

The flasher unit is responsible for automatically switching the lamps off and on. The components used most frequently in the direction indicator are those for switching indicator lights. If the flasher unit is defective, the spare part must be replaced - the Simson MZ is installed in the flasher relay in the engine compartment of the vehicle.
When replacing the flasher unit, the number of connections must be taken into account - now flasher units are available with both two and three connections. It should also be noted whether the spare parts are compatible with LED or conventional bulbs.

Flasher units are available in 6V and 12V versions. The 6V flasher units are suitable for the Schwalbe, Sperber and Habicht models, while the Simson S51 and S70 as well as the MZ ETZ 125 to 250 are better equipped with a 12-volt flasher unit. A high-quality flasher unit can also be recognised by the fact that it is equipped with foam rubber. This serves as a buffer and provides stability.


flasher unit

indicator carrier

A flashing light holder serves as a motorcycle accessory for attaching the flashing lights to the front and rear parts of the motorcycle. These are available for round or square turn signals. The front indicator lights are mounted on the right and left side of the telescopic fork bars with the corresponding indicator light carriers. The rear indicator lights are attached to the mudguard or to the seat screw connection with the appropriate screw connection. The diameter of the mostly galvanized or chrome-plated flashing light carriers is between 10 - 15 mm. For chrome-plated accessories, regular care with special care products for chrome must be observed. Especially in winter, damage (rust) caused by road salt or brine to these accessories can occur without sufficient care.
indicator carrier

blocking tool

The blocking tool for Simson and MZ is mainly divided into two different variants. The gear blocking tool is used, among other things, to open or fix the Variomatik on Simsonmopeds with a continuously variable automatic transmission. It is usually made of solid steel and has appropriate teeth which engage in the pulley teeth and thus prevent unwanted rotations. There are also locking tools for spark plug threads of two-stroke engines, which are also known as piston stoppers. This blocks the engine so that, for example, the nut on the crankshaft can be removed unhindered. Of course, blocking tools can also be produced by yourself. For safety reasons, however, such experiments should be avoided and no risk should be taken, especially as the costs for a high-quality blocking tool in workshop quality are very limited.

on-board tool kit

The on-board tool kit at Simson and MZ was not, as it is today, only a real emergency tool, but was composed in a meaningful and well thought-out way. There was no wide network of workshops and no ADAC. Minor repairs were carried out by the born GDR citizen himself. This did not only concern a simple exchange of the spark plug, also a Bowden cable or a light bulb could be changed without additional special tools. It was even possible to remove the carburettor for cleaning purposes or to dismantle a wheel and repair the hose with the on-board tool kit at the roadside. The on-board tool kit was located either under the left side cover next to the battery or under the folding bench seat.In the tool wrap there are:two mounting levers, double open-end wrench (8 and 9 mm, 10 and 13 mm, 12 and 14 mm, 17 and 19 mm), spark plug socket wrench, socket wrench 10 and 13 mm, hook wrench for the manifold, slotted screwdriver small and large, combination pliers, feeler gauge and a spare candle.Depending on the type, the number and size of the double open-end wrenches varied. Even the combination pliers were not included with every model.
on-board tool kit

bougier tube

A bougie tube is a predominantly black hose made of robust plastic. On Simson and MZ two-wheelers, this hose is primarily used as a supporting element for the orderly routing of several cables. In addition, the Bougie tube has insulating properties and thus protects the cables from breakage or damage. They are available either by the metre or in various lengths. Depending on the number and thickness of cables, these practical insulation tubes are available with an inside diameter of approx. 4 mm to 10 mm. In order to be able to pull out the cables easily and above all individually during repairs, one should prefer as generous a diameter as possible.

brake fluid

Brake fluid is used in hydraulic brake systems to transmit the force from the brake cylinder to the brake pads. As a rule, this liquid is based on glycol. Glycol is hydroscopic. That means glycol is water-binding. Even when the brake system is closed, the brake fluid gradually accumulates more and more water, making it increasingly dangerous for the motorcyclist. If there is a certain amount of water in the brake fluid, the temperature of the brake pads will be high enough to allow the water to evaporate, especially during hard braking manoeuvres. Bubbles are formed from water vapour, a gas. Unlike liquids, gases can be compressed very easily. The pressure that should actually act on the brake pads is lost in the compressed water vapour. The brake system loses a lot of power and becomes ineffective in the worst case. Experts therefore recommend renewing the brake fluid annually, but at least every two years.

ATTENTION, PLEASE:
All work on the brake system should only be carried out by people who have the necessary specialist knowledge and appropriate tools! In case of doubt, you should contact the specialist workshop you trust, at least for the brakes.
brake fluid

brake lever

Brake levers are devices with which the brakes of motor vehicles - and thus also of motorised two-wheelers - are actuated. A distinction is made in brake levers between the handbrake levers and the foot brake levers, also known as pedals. On motorised two-wheelers, both hand and foot brake levers are usually located on the right-hand side of the vehicle - the hand brake lever on the handlebar, the foot brake lever at step height.
The (tractive) force is transmitted from the brake lever to the brake either mechanically or hydraulically. Mechanically, the force is transmitted via a wire rope, which is covered by a flexible but pressure-resistant sheath (the so-called Bowden cable). Hydraulic brakes have two brake cylinders - the master cylinder on the brake lever and the slave cylinder on the brake. They are connected to each other by a pressure line. When the brake lever is actuated, pressure builds up in the master cylinder, which is transmitted to the slave cylinder via the pressure line.
Simson mopeds and MZ motorcycles are - depending on the model - equipped with mechanical or hydraulic brakes. Brake levers should be maintained and serviced regularly, and especially with mechanical brakes it should be noted that the wire rope wears out with prolonged use, which is noticeable in the fact that the brake lever already gives way with slight pressure.

brake lever

brake light contact

In the case of two-wheeled vehicles, brake light contacts are those components of the braking system via which a connection to the brake light is established. They cause the brake light to illuminate when the braking process begins - and to extinguish vice versa as soon as it ends. On Simson mopeds and MZ motorcycles the brake light contacts are located on the brake light contact screw. The contact tongue on the one hand and the grooved pin on the other are attached to it. While the contact tongue serves to connect the cable to the hub, the grooved pin is the counterpart to the contact lug attached to the brake cam. The brake cam is used to operate the brake linings of the disc and drum brakes of two-wheeled vehicles, thus initiating or stopping the braking process. When braking, the brake cam is shifted so that the brake lining is pressed onto the disc or drum of the brake and at the same time the contact lug touches the notched nail. The brake light therefore lights up as soon as the braking process begins. If the brake is released, the contact is interrupted again and the brake light goes out. Brake eye contacts are comparatively delicate two-wheeler components that have to be replaced from time to time. If the brake light does not illuminate during braking, a defective brake light contact may be one of the possible causes.
brake light contact

brake light switch

The brake light switches of a two-wheeler are used to operate the brake lights. These are attached to the rear part of the two-wheeler and are activated when the cyclist applies the brake lever of the front brake or the brake pedal of the rear brake, so that the following traffic is informed of the incipient braking process.

On two-wheelers, both the front and rear brakes are generally connected to the brake lights and both are equipped with a brake light switch. Due to the different construction of the handbrake (lever) and the footbrake (pedal), the brake light switches for the front and rear brakes also differ in their construction in most cases. On some Simson mopeds and MZ motorcycles, however, the brake light switches are suitable for both the front and rear wheel brakes. In addition to these electromechanical brake light switches, there are also models that are actuated by the pressure build-up in the brake system itself. Brake light switches should be serviced together with the brake system regularly (at the latest every approx. 5000 kilometres) and replaced if necessary.
brake light switch

brake cams

The brake light switches of a two-wheeler are used to operate the brake lights. These are attached to the rear part of the two-wheeler and are activated when the cyclist applies the brake lever of the front brake or the brake pedal of the rear brake, so that the following traffic is informed of the incipient braking process.

On two-wheelers, both the front and rear brakes are generally connected to the brake lights and both are equipped with a brake light switch. Due to the different construction of the handbrake (lever) and the footbrake (pedal), the brake light switches for the front and rear brakes also differ in their construction in most cases. On some Simson mopeds and MZ motorcycles, however, the brake light switches are suitable for both the front and rear wheel brakes. In addition to these electromechanical brake light switches, there are also models that are actuated by the pressure build-up in the brake system itself. Brake light switches should be serviced together with the brake system regularly (at the latest every approx. 5000 kilometres) and replaced if necessary.
brake cams

brake caliper

The brake caliper is a component of the disc brake of motor vehicles, including motorised two-wheelers such as MZ motorcycles and Simson mopeds. Drum brakes, on the other hand, do not have a caliper due to their different design from disc brakes.
With the disc brake, the purpose of the brake calliper is to apply tension to the brake linings arranged on both sides of the brake disc, thereby slowing down the movement of the disc and finally bringing it to a standstill. With hydraulic brakes the brake calliper is actuated by pistons, with mechanical brakes by pressing the corresponding hand or foot brake lever. The brake calliper is attached to the so-called torque arm, which is fixed opposite the brake disc. Brake calipers are usually made of cast iron.
Brake calipers of Simson mopeds and MZ motorcycles have to be checked regularly during the maintenance of the brake system. It is particularly important to ensure that both brake linings are evenly worn, as uneven wear is an indication that the brake linings are tensioned to different degrees by the brake calliper.

Brake caliper - Brake caliper

CE marking

A marking affixed at the discretion of the manufacturer which declares that the product placed on the market complies with the applicable requirements. The manufacturer is obliged to affix the CE marking to certain product groups.

choke

The choke is also known as the starter flap and serves as a starting aid. This is controlled manually and ensures a richer fuel mixture during starting and warm-up (fuel content is increased). For this purpose the choke consists of a further petrol nozzle, which is located at the outlet of the carburettor. The air intake is regulated by means of an air flap. In order to avoid excessive fuel consumption and sooting of the spark plugs, the choke should be taken back after the warm-up phase. The older Simson models, which still have an NKJ carburettor, are equipped with a (real) choke. The choke should not be confused with a start carburettor, which you will find on Simsonmopeds with the carburettor types BVF 16N1 and BVF 16N3 or on MZ with BVF or Bing carburettors. The greasing is done by the start carburetor lever, which is usually placed directly under the throttle grip. But colloquially this variant is also called Choke. If the choke has no or insufficient effect, thorough cleaning of the carburetor or nozzles may help in many cases. However, the optimal carburettor setting is often also a problem-solver. The exchange is also possible and sometimes useful.

damping insert

The damping insert is a component of the exhaust systems of two-wheelers. The damping insert is pushed into the end piece of the exhaust system of the moped and serves to reduce the so-called muzzle noises, which occur when the exhaust gases exit the exhaust system.
Damping inserts for Simson mopeds have been developed in different versions. In addition to the standard model, a double-tube damping insert was also produced (which was installed ex works in the Simson Sperber SR4-3, for example) as well as a special damping insert for the so-called cone end piece. This is functionally identical to other end pieces, but has a shape reminiscent of the end piece of cigars, so it is pointed. The tip bag end piece and with it the corresponding damping insert were used in the models of the Simson bird series - Simson KR51/1 "Schwalbe", KR51/2 "Schwalbe", SR4-2 "Star", SR4-3 "Sperber" and the SR4-4 "Habicht".
During the care and maintenance of the exhaust system, the damping insert is pulled out and should be removed by burning or brushing off the oil carbon coating that adheres to it during prolonged use.

damping insert

DEKRA - DEKRA - German Motor Vehicle Surveillance Association

DEKRA is a group of companies which emerged from a testing company founded in 1925 and which focuses on the testing of motor vehicles and technical equipment.

rev counter

The tachometer shows the driver the current engine speed. With the luxury models of Simson and MZ also a mechanical rev counter was in the offer.
Similar to the speedometer, the tachometer was driven mechanically via a flexible shaft. Whether a tachometer was really necessary for the common Eastmoppeds, the spirits argue about it. Below the effective speeds the engines do not react to the throttle grip and above the rated speed the engines react with an above-average noise level and violent vibrations. Even a nervously wriggling hand won't change that.
For racing and tuning fans, however, the rev counter is more important than the speedometer. In the case of engines that are moved in the limit range, the exact speed is one of the most important information for the driver. Overrevving means high wear and tear and in racing often the final end for the engine.

Today, the engine speed can also be determined electronically. Via a tap on the ignition coil, a microcomputer converts the ignition pulses into engine revolutions.



rev counter

nozzle gauge

Nozzle gauges are hardened steel pins which are enclosed in so-called plastic lamellas. They serve as a practical tool for checking and adjusting the individual nozzles and thus belong to the group of tools for maintenance work on the carburettor. With the help of these pins, most inconsistencies, such as deviations in the nozzle diameter or signs of wear, can be detected quickly and easily. But this also exposes nozzles that have become unrecognisable. For Simson and MZ, nozzle gauges are available as sets in sizes from 0.45 mm to 1.50 mm or from 1.50 mm to 3 mm and are naturally part of the basic equipment of passionate screwdrivers.

EG/ECE - type approval

Basically like an ABE. However, the scope refers to all member states of the European Community and other participating states. The part is then provided with an 'E' test mark, the number behind it is the country code. Simply install and carry papers (if enclosed) with you.

inscription

Registration is not an official term. The correct designation is change acceptance and is carried out with the help of an ABE or a TG. A correction of the vehicle documents takes place at the 'next opportunity' but can also be necessary immediately (e.g. in the case of a change in performance). In the new federal states only DEKRA is allowed to make entries, in the old federal states only TÜV.

individual acceptance

This is necessary for vehicles that deviate greatly from the standard type due to extensive conversions. In addition, damage that has been found to be defective will also be checked for proper repair via individual acceptance. The acceptance is carried out by a technical testing organisation.

ELBA

The abbreviation ELBA stands for "electronic charging and flashing system", a technical innovation that was installed in Simson mopeds from the mid-1980s onwards.
The ELBA replaced the traditional charging system of the Simson mopeds and supplemented it with an electronic flasher unit. A special feature of the ELBA compared to the batteries used until then is that the charging current is regulated as a function of the state of charge of the vehicle battery. When the battery is fully charged, the charging current is automatically switched off at the ELBA so that the battery can no longer be overcharged. The automatic switch-off takes place via a so-called thyristor. This is an electrotechnical component that switches itself off when a certain minimum current (of the holding current) is undercut and thus becomes non-conductive.

The ELBA was first used in 1986 on the Simson SR50/80, the successor to the legendary Simson "Schwalbe". This first version was an ELBA with 6 Volt (V). Since 1988 ELBAs with 12 V were used in all newer Simson models.


ELBA

exploded view

An exploded view is a kind of graphic representation in which a complex object consisting of several individual parts is represented in such a way that the individual parts are spatially separated from each other - so that it looks as if they are flying apart in an explosion.
Explosion drawings are used for motorised two-wheelers in particular for engines. This type of representation has the advantage that the position of the individual components of the engine in relation to each other and thus their interaction is illustrated. If exploded drawings are used in spare parts catalogues, the individual assemblies and components are often provided with order numbers. This has the advantage for the customer that he can immediately identify a defective part even without knowledge of the correct technical term and order the suitable spare part. Explosion drawings are also frequently used for assembly instructions, as they can be used to explain the individual steps of assembly or disassembly particularly well. Exploded views were used by both Simson and MZ and can be found in (historical) spare parts catalogues or can be ordered as wall posters.
exploded view

bellows

The bellows are hoses made of plastic, rubber or leather, which are elastic and can be stretched or compressed like an accordion. Its function is to seal machine parts which mechanically move into each other (and therefore "stretch" or "compress" in their overall length) and thus protect them from external influences and contamination.
On older motorised two-wheelers - and thus also on many MZ motorcycles and Simson mopeds - bellows are often found on the "e;motorcycle fork"e; the so-called front wheel suspension, where they protect the fork sealing rings located between the inner and outer fork tube. On newer motorised two-wheelers, bellows are almost exclusively fitted to off-road models and Enduros. Bellows are robust and not particularly susceptible to wear. However, they can be damaged by contact with sharp objects and should therefore be checked from time to time for leaks.
bellows

suspension strut

A suspension strut essentially consists of two components. On the one hand from the actual spring, on the other hand from the shock absorber. The spring compensates for road unevenness, the shock absorber brakes the spring and thus prevents the chassis from rocking up.

Depending on the version, both Simson and MZ were fitted with partially adjustable suspension struts. Depending on the load, the driver can gradually adjust the preload of the springs and thus adjust the road holding to the payload.
suspension strut

spring bend

Spring manifolds are part of an innovative exhaust mount that can be retrofitted to Simson mopeds and scooters. The use of spring elbows is one way to solve a problem encountered with many Simson models: Especially on older scooters the exhaust is bolted to the engine with a two-point mounting. Since the engine (which rests even on soft rubber bearings) moves several centimetres while the car is running, the exhaust is also set in motion, but cannot move freely enough due to the rigid two-point mounting. As a result, the individual components of the exhaust suspension "cooperate" strongly.
In particular, the elbow nut loosens under the influence of permanent vibration and must be retightened regularly (every few hundred kilometres according to experience reports). If, on the other hand, the exhaust is fixed with spring bendings, the vibration emanating from the engine is considerably dampened and at the same time it is ensured that the exhaust can oscillate freely.
Spring manifolds are hooked into the ball flange on one side and into the holes provided for the damping rubbers on the cylinder on the other side. Spring elbows are wearing parts and should be serviced regularly and replaced if necessary. As a rule, they are supplied as a set with all the components required for the conversion.

spring bend

rim tape

The rim tape protects the hose from damage by the sharp edges of the spoke nipples inside the rim.

The Simson and MZ motorcycles are usually fitted with spoked wheels. The nipples are provided with an internal thread and a slot at the upper end. Without rim tape, the hose would chafe through the sharp edges of the spoke nipples much faster than desired. The classic rim tape is a narrow strip of rubber, with a punched hole for the valve. The ends are glued together and the rim tape holds itself in position by the tension of the rubber alone.

With modern, self-adhesive rim tapes it is even possible to use a tubeless tyre on a spoked wheel.
rim tape

fixed wheel

The term fixed wheel is used in gear technology. For each gear in a sequential gearbox, several gear pairs are responsible for power transmission between the input shaft and the output shaft. The fixed wheel is always the gear wheel that is firmly connected to the corresponding shaft. Its counterpart, the idler wheel, is pushed into the desired position by the shift claw, so it is not frictionally connected to the shift shaft, but can be moved on the axle. Each gear has at least one fixed wheel and one loose wheel on the corresponding shafts. The whole story is always complicated when the loose wheel sits on its own shaft as a fixed wheel. When ordering, you should therefore always pay close attention to the gearing and the exact order numbers. Depending on the viewing angle, the idler gear of a gear on its own axis can also be a fixed gear.
fixed wheel

flange gasket

The flange gasket is located between the carburettor and the intake flange on the cylinder. (with four-strokes on the cylinder head). Their primary task is to seal the intake tract. Especially with older models it should also isolate the carburetor from the high temperature of the engine. This is why the term insulating flange is also used.
If the flange gasket is worn out, the motor draws secondary air. The mixture becomes too lean and the engine overheats. So if you have a clearly too bright candle pattern, you should spray brake cleaner or starting aid spray on the intake duct while the engine is running. If the motor turns higher, it draws in secondary air.
Beware of throttled motorcycles! Here another flange gasket with smaller passage is part of the throttle kit. An exchange for the original part could lead to driving license problems.

flange gasket

feeler gauge

Since the feeler gauge can be pulled apart like a fan, it is often referred to as a fan spy. With this measuring tool exact gap dimensions can be determined. The so-called probes (flat metal sheets), which can be inserted into the gap to be measured, therefore have different thicknesses and are of course marked accordingly. Guide gauges with nine blades and measuring ranges from 0.04 to 0.08 mm with 0.01 mm accuracy or 0.1 to 0.3 mm in measuring steps of 0.1 mm are common for Simson. Alternatively, there is also a variant with 20 sheets from 0.05 mm to 1 mm in 0.1 mm increments. Guide gauges (see also distance gauge) are indispensable for adjusting the breaker contact spacing and the spark plug, among other things. The valve clearance can thus also be checked. Since the probes are often very sensitive and can therefore also bend, one should proceed very cautiously when measuring.

guide mandrel

The guide mandrel is a conically shaped special tool. It facilitates the mounting of the piston pin in the piston. For this purpose, the previously oiled piston pin is placed on the guide mandrel and then inserted into the needle bearing. For pistons with compensating washers, it is recommended to grip a guide mandrel with a press-in tip. Always pay attention to the model-dependent length and diameter dimensions. An appropriate ejector device is suitable for ejecting the bolt. Without special or special tools (guide mandrel and blocking tool), the dreaded "e;piston seizure"e; could quickly occur after a cylinder or piston change due to inaccurately fitting piston rings. The investment in this absolutely affordable auxiliary tool is therefore worthwhile for Simson and MZ owners in any case.

triple clamp

fork oil

It's like gear sand, only liquid from the aggregate. Fork oil is a hydraulic oil which is used for the vibration damping function of a telescopic fork. The fork oil flows through the bores of the damper piston, thus slowing down the movement of the immersion tube and standpipe and preventing the suspension from rocking up.
The damping properties of the fork can be influenced by different viscosities. The smaller the number of viscosities, the thinner the oil and the softer the damping. Oil works temperature dependent. In the winter months a thin oil is recommended, otherwise the fork becomes too hard at sub-zero temperatures. The same oil can already be too soft for sporty riders in midsummer, which leads to a spongy front wheel damping. When changing the fork oil, pay very close attention to the prescribed quantity. In general, the fork oil is always changed on both fork rails at the same time.
fork oil

throttle cable

The Bowden cable, which connects the throttle twist grip with the slider in the carburettor, is called the throttle cable. By turning the throttle handle, the carburetor slider lifts, the air volume in the intake duct increases, more fuel is drawn in and the moped accelerates. The throttle cable lasts very long with good care, but is still one of the wearing parts. The throttle cable must be greased regularly and checked for damage. A sluggish lane rope cannot be operated sensitively and poses a considerable danger if it gets stuck and no longer goes into resting position.
throttle cable

middle part of the skinning

baggage handlers

The original rear luggage carriers of the Simson and MZ mopeds probably served in practice much more frequently as holding brackets for the passenger than actually for transporting luggage. They were too narrow for that, and the retaining rubber only worked in one direction. Losses were virtually inevitable. The side racks were much more popular and also more functional. This meant that even heavy luggage could be transported safely without shifting the centre of mass too high and making the bike unstable.
baggage handlers

Gearbox

The gear is a machine element that changes motion variables. Because of this function, the gearbox is also referred to as a converter element. The gearbox is usually placed between the (driving) motor and a (driven) working machine or - as with motorised two-wheelers - a machine part. Two-wheel gearboxes are connected to a clutch both with the engine and with the machine part. There are several types of gearboxes, whereby gearboxes consisting exclusively of fixed components are referred to as mechanical gearboxes. Mechanical gears are further classified according to the type of power transmission. Gears with gear wheels are particularly widespread. They were also used in most Simson and MZ two-wheelers. Torque transmission in gear units is achieved by the gear wheels moving together with the shafts and axles on which they are mounted. The distance between two gear wheels is always dimensioned so that their teeth can mesh to transfer the rotary motion from one wheel to the other. The speed can be changed by different sizes of the gear wheels and thus the torque can be increased or decreased. Gearboxes of Simson and MZ two-wheelers are lubricated with gear oil and should be serviced regularly.
Gearbox

gear oil

As pistons and cylinders in two-stroke engines are lubricated via the mixture, a suitable gear oil can be used in the gearbox to lubricate the gears, bearings and mechanical seals accordingly. A gear oil GL80W or GL-3 is recommended for the Simson and MZ engines. According to the operating instructions, the gear oil must be changed every 8000 km. Who drives less should change the oil annually, or at least every two years.
gear oil

thread gauge

The thread gauge for metric threads at MZ and Simson is also known as thread comb or thread template. It is used to check the internal threads by means of the light-gap method. The flank, core and nominal diameters as well as the flank angle position and the flank angle pitch can be checked with this fan-like template. The gauge is simply placed on the thread and then held against the light. With a suitable thread, no light should shine through. However, exact deviation values cannot be determined with this thread gauge. Nevertheless, it is ideal for use as on-board tooling and should not be missing in cutting boxes or in a well-equipped workshop.

glass base lamp

Better known are glass base lamps as glass squeeze base lamps or wedge base lamps. They are particularly economical and the incorporation of the socket into the plastic housing moulding is quite uncomplicated. Using the example W2,1×9,5d, the glass crimp base thickness is marked with 2,1 mm, the width with 9,5 mm and the number of contacts with two pieces. In motorcycles made by MZ (e.g. MZ 500 R) or in motorised two-wheelers made by Simson, these lamp types are occasionally used as control or instrument lighting because they have been additionally installed or replaced. Lamps with a glass base are usually very inexpensive, but often do not have a long service life. The StVO also requires an e-mark for use on public roads.

base

The base plate is a component of the ignition system and alternator on motorised two-wheelers. It is also used in Simson mopeds and MZ motorcycles. It is a round metal plate on which a number of components of the ignition system are mounted: Two light coils (one each for the headlight and the rear and brake lights), the ignition coil and the battery charge. Depending on whether the motorised two-wheeler has a breaker ignition or an electronic ignition, there are other components on the base plate. In the case of a two-wheeler with breaker ignition, these are the breaker and the capacitor; in the case of a two-wheeler with electronic ignition, these are the so-called transmitter coil. Above the base plate is the pole wheel, which is connected to the crankshaft by a disk spring (the so-called "e;crescent wedge"e;) and generates a magnetic field as soon as it is set in motion by the crankshaft - which in turn generates electrical current in the coils attached to the base plate.
Base plates are largely maintenance-free, however, the tight fit of all components mounted on the base plate should be checked during regular maintenance of the ignition system.
base

GS - tested safety

A voluntarily affixed marking of the manufacturer for products which are not subject to CE-marking. Product testing is carried out by an independent testing or certification body and is regulated by law.

H4

he H4 is a 12-volt two-filament halogen lamp with two tungsten filaments, one filament for the high beam with 60 watts and the other filament for the low beam with 55 watts. The first presentation of the H4 was already in 1966 and it was actually used for the first time in 1971. The elongated glass bulb is filled with a special halogen protective gas, including bromine and iodine additives. To avoid glare areas, the diffusing lenses for the H4 are also often asymmetrically corrugated. For Simson and MZ there are also H4 lamps with a higher light output (100 / 90 watts). However, these are not permitted in the area of the StVO. You also have to be careful with conversions of MZ and Simson reflectors, which are originally intended for normal incandescent lamps with 25 watts or 35 watts. In principle the conversion is possible, but please always observe the ABE (General Operating Permit). In some MZ motorcycles, as for example in the ETZ 250, the H4 headlight was also installed as standard. The average burning time of a H4 is comparable to a normal light bulb. In contrast, however, the light output of the H4 does not decrease significantly towards the end because no deposits form on the bulb. All halogen lamps should generally not be touched by the bulb, but only by the base.

halogen bulb

Equipping Simsonmopeds and MZ motorcycles with halogen headlamp systems with halogen lamps results in a significantly higher luminous efficacy. The piston is filled with a very precisely calculated noble gas mixture and the tungsten is extra heat resistant. Compared to a normal incandescent lamp, no brown residual particles can settle on the edge inside the smaller halogen bulb. This ultimately does not reduce the brightness of the light. Rather, the tungsten moves as a kind of circuit directly back to the filament. The service life of a halogen lamp for either 6 V or 12 V is therefore correspondingly long. When installing the lamp, make sure that you do not touch the bulb with your fingers. The pedestal, on the other hand, can be touched easily. For Simson S and SR models, among others, complete base plates including light and charging coil are also available. In spite of the numerous advantages, the StVZO only permits halogen lamps to a limited extent on public roads. Therefore one should not only pay attention to the compatibility to the two-wheel electronics, but also to the E-test mark.

master brake cylinder

The master brake cylinder, HBZ for short, is a cylinder used to generate pressure. It first transfers the force to the brake fluid. This causes a power transmission to the pistons in the brake calliper. The pistons in turn press against the brake discs. If the pistons are stuck (e.g. after a very long service life), the brake cylinder, pistons and above all all all seals should be cleaned thoroughly and of course according to precise instructions. If, however, the components are severely damaged, it is worth replacing the main brake cylinder including all affected accessories. These are available for MZ (for example ETZ and TS) and for Simson individually, with handbrake lever or as a set. The Simson models S50, S51 and S70, among others, have drum brakes as standard, which often stand out due to a decreasing braking effect. With the appropriate expertise, they can be converted to disc brakes with suitable master cylinders.

main nozzle

The main nozzle installed in the carburetor is often abbreviated as HD in specialist circles. In the float chamber it is regarded as the largest nozzle. First and foremost, it is responsible for the ideal mixture formation at full throttle, i.e. when the associated slider reaches its highest position. An HD that is too small usually leads to overheating of the cylinder because the mixture is too lean. If the main nozzle is too large, the petrol content in the mixture that is now too rich will be higher and the engine will start stuttering under full load. When replacing the original HD to increase performance, you should therefore always pay attention to an optimal fine tuning. The corresponding spark plug pattern is generally helpful here. Regular maintenance and cleaning intervals are also indispensable.

heart box

Simson mopeds use the term heart box to describe the middle part of the air filter housing - a name that this component owes to its characteristic, heart-shaped outer shape. Further common designations are air filter box, battery box and housing middle part.
The air filter from Simson Mopeds, whose housing includes the heart box, has the task of cleaning the air of minute particles before it reaches the carburettor or the cylinders. The heart box contains the air filter box, a device for holding the air filter cartridge, which is protected by a cover plate. Heart boxes for Simson mopeds are made of plastic and differ slightly in size depending on the type of vehicle they are made for. They are closed on both sides with a side lid.
Heart boxes are largely maintenance-free. However, the air filter cartridge in the heart box must be changed from time to time. On this occasion, the numerous small parts attached to the heart box (such as suction sleeve, battery holder and hole cover) should be checked for tightness.

heart box

heat protection

Heat protection in motorised two-wheeled vehicles is the term used to describe the components with which the exhaust pipe is sheathed. They are also used for Simson and MZ two-wheelers. Since the exhaust pipe of motorcycles and mopeds is generally exposed, it poses a hazard to the rider. To prevent burns from accidental direct contact with the pipe, it is provided with heat protection. This is a semicircular steel sheet which is placed around the outward side of the exhaust pipe. Openings are punched into the steel sheet so that the heat escaping from the exhaust pipe does not accumulate and the pipe is cooled by the airstream.

The heat shield is attached to the front and rear of the exhaust pipe with special clamps. When servicing and maintaining the heat protection, it should be borne in mind that due to its exposed position it is particularly exposed to splashing chippings (all year round) or road salt (in winter), which makes it particularly susceptible to damage and corrosion. To ensure the safety of the driver, the tightness of the heat shield mounting clips should be checked regularly.
heat protection

lifting disc

Simson and MZ single cylinders, in which no cranked crankshaft was installed, often have a lifting disc instead. It consists of a round disc with corresponding punched holes or notches and a primarily centrally positioned pin. The term crank pin is also commonly used. These components are usually differentiated according to the positioning or positioning side on the two-wheeler. There are lifting discs with shaft stubs for the clutch side with 17 mm long pin (MZ ES; MZ TS), for the drive side (mopeds with 50 ccm - S51, S53, SR50) or for the alternator or for the alternator side (KR51/1, SR4, S50,SL1 Mofa). In addition to the perforation, you should pay attention to the exact dimensions (journal length, diameter) and to any accessories that may be required, such as the disc bushing.

lifting pin

The crankpin belongs to the components of the crankshaft and is off-centre of the KW-axis. The connecting rods (push rod) and pistons are attached to it. The lifting trunnions are connected to the shaft trunnions by so-called cheeks. Counter-rotors (MZ 1000 S /ST / ST) with in-line two-cylinder and pistons running up and down alternately are equipped with two lifting pins. The model 1000 S has a 180 degree crankpin offset. The crankpin offset is the distance of the crankpin measured from the middle of the crankshaft. This is used to calculate or determine the stroke of the piston. A higher distance to the centre produces a higher leverage effect and thus more lift. The pin, whether for Simson or MZ, usually also includes the appropriate needle bearing. Hub pins including connecting rods with needle bearings are also available as a set. The needle bearing conrod thickness is the decisive factor here. For the ETZ125 and ETZ150, for example, it is 17.4 mm. Among others, Simson SR4-2 Star, SR4-1 Spatz and SR4-4 Habicht have a lift pin diameter of 16 mm.

insulating flange

Sits between cylinder and carburetor. Prevents overheating of the carburettor due to increased insulation. The material is bakelite or plastic.

KBA - Federal Motor Transport Authority

Issues the ABE and ABG (national) as well as the EC/ECE type approval "E1" for motor vehicles and vehicle parts. It also maintains the central traffic register (traffic offender file).

KBA number

The KBA number is a unique number under which a vehicle or component is registered with the Federal Motor Transport Authority.

piping

In vehicle construction - and thus also in motorised two-wheeled vehicles such as Simson mopeds and MZ motorcycles - the term "piping" is used to describe the edge reinforcement of another object which is not firmly attached to it. Keder are usually made of rubber and are therefore colloquially known as "rubber piping". They have the related functions of gently impinging a wrapped object - such as plastic, metal or glass - on another object and sealing the space between them. Keder are therefore also used for seals, among other things. For motorised two-wheelers, piping is used for lamp housings, skirting boards, knee plates and motor tunnels.
Keder are wear parts and can become porous over time. They should therefore also be checked regularly for Simson mopeds and MZ motorcycles and replaced if necessary.
piping

Chain - Drive chain

A drive chain is the so-called traction means in a traction means gear - i.e. a gear that serves to transmit torque from one shaft (or the gear connected to it) to another. In contrast to a gear transmission in which the gears mesh directly with each other, in a traction drive they are placed at some distance from each other. This distance is bridged by the drive chain, which wraps around both gear wheels and thus transmits the torque of the driven shaft to the non-driven shaft.
Drive chains are also used on motorised two-wheelers such as MZ motorcycles and Simson mopeds. The advantages of drive chains include their comparatively low manufacturing costs and high efficiency. However, drive chains also have an increased need for care and maintenance, with particular attention being paid to adequate lubrication and the correct chain tension. With good care, the drive chain of a motorcycle or moped can last up to 30,000 kilometres, but with poor care it is worn out after just a few thousand kilometres.
Chain - Drive chain

chain alignment tester

As the name already indicates, a chain alignment tester is used to check the chain or toothed belt alignment on the MZ motorbike or Simson moped by applying it to the chain wheel. The primary purpose of this test is to avoid signs of wear on the chain, sprocket or sprocket, which can ultimately lead to a drop in performance. Ideally, the tester is equipped with a spot laser. If the laser dot runs 100 % along the chain plates after the application, the rear wheel and chain wheel are precisely mounted on the axle. Otherwise they must be readjusted and re-tested. The check by means of a chain alignment tester takes only a few seconds and, in contrast to self-constructions, is characterized by an extra high accuracy.

chain box

In the Simson and MZ models, the rear part of the encapsulated drive chain guide is referred to as the chain box. The chain box, usually in two parts, encloses the chain pinion on the sprocket side and protects the chain from dirt and moisture.
Both with the early models of Simson, and with the first models of MZ, the chain boxes were from aluminum - injection moulding. Later models will be made of black hard plastic.
The chain box is part of the encapsulated chain guide on almost all Simson and MZ models. The chain runs from the motor-side chain pinion through a chain tube into the chain box and back again. Thus, the drive chain is largely protected from environmental influences and lasts accordingly long.
In contrast to the Simsons, the chain box at MZ has an additional function. It also serves as a mounting for the speedometer shaft drive.


chain box

Chain wheel driver

The sprocket driver is the name given to the sprocket of the two sprockets of two-wheeled vehicles with chain drive to which the force is transmitted. It is therefore the driven gear of the gear pair. Its counterpart is the drive wheel (also called small chain wheel on motorised two-wheelers), which transmits the power via the drive chain to the sprocket driver. The DIN designation "sprocket" has not established itself for two-wheelers in colloquial language. Chain wheel drivers are also fitted to MZ motorcycles and Simson mopeds, which have a chain drive.
Since most motorised two-wheelers are equipped with a rear wheel drive, the sprocket driver is usually located on the rear wheel and is therefore also called the "rear sprocket driver". It is pushed onto the hub, which in turn is connected to the shaft of the rear wheel. For the care of sprocket drivers it is crucial that the drive chain is always well lubricated, otherwise the teeth of the sprocket driver will wear out quickly. The sprocket driver should be replaced as soon as its teeth become blunt.
Chain wheel driver

chain hose - chain protection hose

The two chain hoses connect the chain box with the motor housing and thus form an encapsulated system for the drive chain.
The chain tube is made of rubber. A bellows at the end provides the necessary flexibility in length. This compensates for the increasing distance between the motor housing and the chain box when the chain is retensioned.
The encapsulated guide protects the drive chain from dirt and moisture, which considerably extends its service life. However, encapsulation often leads to neglect of chain care. You don't see broken reels. The condition of the chain can only be inspected after dismantling the motor housing cover.
Special attention should be paid to the bellows. With increasing age, the material becomes brittle and cracks appear. If moisture penetrates there, it can no longer evaporate and accumulates in the chain box.


chain hose - chain protection hose

Kickstarter - Kickstarter shaft

The kick starter is a fold-out lever used to bring the engine to the speed required for starting. For this purpose there is a pedal at the end of the kick starter, which is operated with some strong kicks. The kick starter is connected to the kick starter shaft at its end opposite the pedal. It transmits the force released during operation of the kick starter by transmission either to the crankshaft (with the primary kick starter) or to the so-called transmission layshaft (with the secondary kick starter). The starter motor is actuated when the engine pistons have been moved so far that they exceed the top dead centre, i.e. the highest position they can reach in the cylinder, as the ignition is then triggered.
Some larger single-cylinder four-stroke engines in particular - including the MZ models with a Rotax engine - require a great deal of force to move the piston this far. Kickstarters were also used on Simson Mokicks and some older MZ motorcycles - on younger motorcycle models, electric starters were used.
Kickstarter - Kickstarter shaft

Sprocket - Sprocket

The small chain wheel is the driven (motor-side) of the two gear wheels on two-wheeled vehicles with chain drive. The technically correct term for this component is "sprocket" according to DIN, but this term has not become established in everyday language for motorised two-wheelers. The small chain wheel is connected to the shaft via a hub and transmits its torque via the drive chain to the driven gear wheel, which is usually located on the rear wheel of motorcycles and mopeds. The small chain wheel is also called this if it actually has a larger diameter than the driven gear wheel. Also MZ motorcycles and Simson mopeds, which are equipped with a chain drive, have small chain wheels. During their care and maintenance, it is particularly important to ensure that the drive chain is always sufficiently lubricated, otherwise the small chain wheel will also wear out more quickly. The small sprocket must be replaced as soon as its teeth begin to become blunt, otherwise the drive chain may lose its tight fit.
Sprocket - Sprocket

moped

The term 'moped' covers motorised two-wheelers and tricycles with the following characteristics: They are motor vehicles with a maximum design speed of 45 km/h and a cubic capacity of up to 50 cm³ or with an engine power of up to 4 kW for electric motors.

The term "moped" was first introduced in 1953. Since then, the legal requirements have changed several times. Today, mopeds in the EC vehicle classes L1e and L2e are determined uniformly throughout Europe. The types of motorcycles that are counted as mopeds are bicycles with an auxiliary motor, mopeds, light mopeds, mopeds, mokicks and scooters. Three-wheeled mopeds are mainly small vans such as the Ape and the Microcar as well as ambulances such as the Simson Duo.

A driving licence of the EU driving licence class AM is required for driving small motorcycles, which can generally be acquired from the age of 16, in the federal states of Thuringia, Saxony and Saxony-Anhalt as part of a model test from the age of 15. Driving on motorways is prohibited for mopeds, as a maximum design speed of at least 60 km/h is required. Samson also made mopeds. Until today the Simson S50/51 is the most built moped in Germany.

knee plate

A knee plate on motorised two-wheelers from Simson and MZ is a mudguard that is bolted to the frame at right angles to the vehicle axle at the front of the vehicle. Knee plates attach below the tank and cover the engine and manifold. They are so wide that they shield the driver's slightly splayed knees from the front when sitting. Knee plates are screwed to the frame. Depending on the type of vehicle, the knee plates may consist of one continuous sheet or two individual sheets and have recesses of different sizes for the tank and manifold.
The function of knee plates is to protect both the driver and the vehicle engine against splashing moisture, but above all against chippings (small stones) and other small objects that could damage the engine and injure the driver. The knee plate can be damaged by the impact of chippings and other hard objects. It may therefore be necessary to repaint or dent it from time to time.
knee plate

knee cushions

Knee cushions belong to the group of frame parts and are attached to the left and right sides of the tank. Oval-shaped knee cushions are particularly popular with two-wheeled classic cars and motorcycles from the former GDR. These include for example the Simson AWO Sport or AWO tours as well as the MZ models ES, TS, RT and ETS. Since these knee pads mostly consist of robust rubber, they are also called knee rubbers. There is certainly some disagreement about the look, but it has many advantages in terms of protection and comfort. Especially on bumpy roads and the associated vibrations the knees are noticeably relieved by the padding. In addition, the tank or the tank painting is also spared. The size of the knee cushions depends on the retaining plate, which can also be ordered separately. Whether one decides now for black, red or light knee rubbers with continuous or only partially incorporated structure, is left to each biker of course. There are normally no special approval regulations for knee cushions as long as they are securely mounted.

plunger

The cylindrical piston is a part of the cylinder in which it moves up and down. In this way it converts pressure into movement, which ultimately leads to the drive. In a Simsonmoped, the piston reaches a speed of approx. 15 m per second at 60 km/h. The basic components of the piston include the piston crown (valve pick-up function), the piston skirt (guiding task in the cylinder barrel), the piston pin (connection between piston and connecting rod) and the piston rings (sealing, heat dissipation and lubrication). On older MZ and Simson models the pistons are still made of cast iron. Newer versions already have an aluminium casting alloy in the gravity die casting process. In the piston ring grooves of the two-stroke pistons, locking pins are also integrated to prevent jamming or twisting. On some motorcycles up to the middle of the 50s, nose pistons were also used for the flushing process and for gas exchange. With original Simson and MZ pistons you are almost always on the safe side. In the case of replicas (due to lack of availability), it is essential to pay attention to the exact nominal dimensions. If these dimensions are not met, capital defects can quickly occur. In addition, the piston change itself should always be carried out in accordance with new piston rings. Complete sets with cylinder, cylinder head, rings and pistons are also available.

piston pin

The piston pin is the connecting piece between piston and connecting rod. It serves to transmit power to both components and is usually located floating or with very slight play in the piston or connecting rod eye. For weight optimization, the steel pin is hollow on the inside with either a constant or centrally reinforced cross-section. In many MZ and Simson two-stroke engines, however, the piston pin bore is interrupted to avoid duct connections. Simson piston pins normally have a diameter of 12 mm. In repairs, changing the piston pin alone is often not sufficient because the piston rings or even the entire piston are almost always affected. Therefore, the bolt is often offered in various set variants. Depending on requirements (e.g. piston seizure = pin fit too tight), it also contains the carburettor, cylinder head and cylinder. Particularly with tuning pistons one should pay attention however exactly to the permission references of the StVO. The type, displacement and dimension data as well as the number of piston rings are also important before installation, because there are considerable differences between Schwalbe, AWO, ETZ & Co.

piston ring

Piston rings made of metal (Simson mostly used nodular graphite iron) belong to the interchangeable parts of the piston. Unlike a normal ring, they are not completely closed. The small opening is also called a ring joint. In addition, the rings have an internal locking device and the pin is located in the middle of the piston ring groove. The piston ring basically fulfils three important tasks: Sealing of combustion chamber and crankcase; combustion heat dissipation from piston to cylinder wall; lubricating oil metering between cylinder wall and ring. In addition to the number of piston rings, the dimensions are of course also important. On the Simson S51, for example, the piston dimension is located on the underside of the cylinder or on the previously cleaned piston crown. During installation, the correct piston ring joint (distance between the piston rings) must also be observed. Too much height also leads to ring fluttering. This noticeably reduces the performance and ultimately leads to breakage. In general, it is therefore of little use to mount new piston rings on a heavily worn piston. It makes much more sense to change both components. In the best case a piston ring pliers is suitable for the correct assembly of the pin rings.

compression pressure gauge

As the name suggests, the highest possible pressure of the piston in the cylinder is determined with a compression pressure gauge (also called a compression pressure tester). The measurement results in "Bar" are displayed on a circular scale by means of a needle. Simson models should have a value between 8 and 10 bar. If the compression pressure is much lower, this could be caused, among other things, by stuck piston rings or wear on the cylinder. The most reliable results are obtained when the engine has already warmed up and the throttle valve is fully open. Compression pressure gauges are available either with screw thread or with rubber cone, which can then simply be pressed into the spark plug opening to fit exactly. This tool is particularly needed for restorations or for two-wheelers that have been out of service for a long time and need to be made fit for new registration.

condenser

A capacitor is a (passive) electrical component that serves as an AC resistor in an AC circuit. In simplified terms, a capacitor consists of two surfaces that are electrically conductive (the electrodes), between which an insulating material (the dielectric) is located.

On motorised two-wheelers with breaker ignition, the capacitor is mounted on the base plate together with the breaker. While the interrupter switches the ignition on at the optimum ignition point and then immediately switches it off again, the capacitor absorbs the current surge caused by the self-induction (starting the engine without an external energy source) and stores its electrical energy so that it is withdrawn from the ignition contacts. In addition, the capacitor prevents the formation of sparks at the contact of the breaker. If the capacitor does not work properly, the ignition coil energy will be lost and the ignition timing will change. Capacitors are also used in MZ motorcycles and Simson mopeds. They are wear parts and must be replaced regularly.
condenser

contact flag

The contact lug is attached to the brake cam, a component of the braking system of motorised two-wheelers. The brake cam is used to operate the brake linings and thereby initiate or stop the braking process. When the brake is operated, the brake cam is also displaced so that the brake lining is pressed onto the drum (with a drum brake) or disc (with a disc brake) and at the same time the contact lug touches the so-called notched nail. This is located on the brake light contact screw, to which the cable leading to the brake light is also attached, so that a connection is made to the brake light - which therefore lights up as soon as the contact lug hits the core nail. The tight fit of the contact lug on the brake cam should be checked on Simson mopeds and MZ motorcycles as part of the brake system check.
contact flag

KTA - Motor vehicle technical office

Was a licensing authority of the former German Democratic Republic (GDR) based in Dresden and was affiliated to the KBA as a branch office after the fall of communism.

spherical flange

The spherical flange is a component that is used together with the so-called calotte on Simson mopeds to retrofit the exhaust attachment. This should solve a problem that occurs with many - especially older - Simson models. With them the exhaust is rigidly screwed to the engine - but only at two points. As the engine can move several centimetres in its rubber bearings during driving, the exhaust is subjected to strong vibrations that are not always synchronous, loosening the mounting of the exhaust and generating noise. Calotte and ball flange ensure that the exhaust can move freely in all directions. The calotte is a metal ring a few centimetres wide which is placed on the exhaust, the ball flange is a narrow metal ring to which two spring elbows are attached which are hooked with their other end into the cooling fins. The spring elbows are wear parts and should be replaced every few years.
spherical flange

ball lamp

Ball lamps are incandescent lamps with a round or spherical bulb. They have a voltage of 6 V or 12 V and are primarily used as flashing lights in the Simson S51, S53 and S70 or as stoplights. In addition, ball lamps can also be used for indicator or high beam control, as speedometer lighting or for idling indication in many ETZ models. The voltage and wattage must always be adjusted in accordance with the vehicle's electrical system. Equally important is the adjustment with the StVZO, because some ball lamps, often coloured versions, are not permitted in Germany or in Europe. With an existing E-mark, Simson and MZ owners are on the safe side.

clutch basket

The clutch basket is a component of the clutches of motor vehicles and is also used in Simson mopeds and MZ motorcycles. Couplings are machine elements for connecting two shafts. The connection makes it possible to transfer the rotation (and thus the torque) of one shaft to the other - in the case of motor vehicles from the crankshaft coming from the engine to the clutch shaft leading to the gearbox. More precisely, the torque is transmitted from the clutch basket connected to the crankshaft and via the clutch discs toothed with it to the clutch plates (friction linings), which in turn are connected to the clutch shaft. When the clutch is actuated (engaged), the clutch discs and plates are compressed by a spring so that the force can be transmitted. The connection is released again when the clutch is disengaged (idling). The clutch basket has recesses into which the teeth of the clutch discs - designed as gearwheels - engage. If replacement is necessary as a result of wear, the clutch basket and clutch disks should always be replaced together, as they have worn each other out after prolonged operation.
clutch basket

clutch plate

Clutch plates are generally also referred to as clutch discs. The package, which is force-locked by springs and pressure plate, is located in the so-called clutch basket. The inner plates, equipped with friction linings to increase the coefficients of friction, are rotationally fixed to the shaft. The outer plates (intermediate plates), which are usually made of steel at MZ and Simson and form a connection with the clutch basket through recesses, sit alternately between them. While the functional principle of multi-plate clutches is almost always comparable, there are differences in the number of plates depending on the model. The thickness of the slats is also decisive. If the clutch hardly or no longer separates, the clutch plates are often warped or stuck together. In this case, of course, only individual slats could be replaced. However, it would make more sense to change all the inner and outer slats.

clutch disc

The clutch discs (discs with outer friction linings and inner clutch plates) are alternately arranged according to the sandwich principle in the driving clutch basket. The connection with the coupling shaft is achieved by means of toothing. The entire disc pack is firmly pressed together by a pressure plate and, depending on the model, by one or more springs. This keeps the connection between gearbox and motor closed. Only when the clutch lever is actuated does this connection open thanks to the pressure rod, because this relieves the spring pressure. Most Simson and MZ models are equipped with a multi-plate or multi-plate clutch. If the clutch is subjected to heavy loads or set incorrectly, the plates may overheat. These then often show a bluish discoloration and / or are warped. In the case of a "slipping" coupling, the contact pressure may be too weak. In this case you should not only change the clutch discs, but also the springs.

clutch shaft

The coupling shaft in the ball bearing is a part of the gearbox. The thrust washer and the gearwheels sit on it. The clutch shaft contains the clutch pressure rods and the cylindrical roller. The force of the clutch is transmitted to the clutch shaft so that it can work in harmony with the output shaft including the associated gears and the shift fork (example Simson with M53 gearbox). (Simson S51, KR 51/2 = Draw spline shaft with switching balls) When installing a new coupling shaft, ensure that it is secured with an appropriate circlip. For the Simson engines M541 and M741 (4-speed), for example, the size 17 x 1.0 is required. You should also check that the previously removed ball bearing is undamaged.

clutch gear

The clutch gear is part of the primary drive. It is located on the clutch basket and is connected to the drive pinion. The number of teeth depends on the design of the clutch gear. For example, the Simson S51, S53, SR50 and KR51/2 models have 65 teeth and the S70, S83 and SR80 models have 62 teeth. There are also clutch gears for centrifugal clutches, which are installed in the Duo4/1 and in the KR51/1S (Schwalbe). If wear occurs, both components (clutch gear and drive pinion) should be replaced for optimum tuning.

charging station

The charging station is part of the Simson moped electrics. Together with the so-called tail light choke, it forms a mechanical unit whose task is to charge the battery while the engine is running and to regulate the flow of electrical current from the light coil to the tail light.
The charging system and rear light choke prevent the bulb of the rear light from being destroyed by overvoltage ("burning out"). They are necessary because the alternating current generators installed in Simson mopeds have the property of delivering an almost constant voltage, independent of speed, only at nominal load ("full throttle"). To keep the voltage constant, the charger contains a rectifier diode that converts the AC voltage supplied by the charging coil into DC voltage that can be stored by the battery. The taillight choke connected to the charger is a coil which limits the current flow by increasing the AC resistance with increasing frequency (speed).
As part of vehicle maintenance, the charging system should also be checked at regular intervals. The audit includes details: The blocking effect of the rectifier diode, the charging current, the battery voltage at the charging system, the alternating voltage upstream of the charging system and the voltage downstream of the charging system (without battery charge).

charging station

light motorcycle

A light motorcycle is a small motorcycle which, according to § 2 No. 10 of the Vehicle Approval Ordinance (FZV) of 1 March 2007, has a cubic capacity of at least 50 cm³ and at most 125 cm³ and whose rated power does not exceed 11 kW. In Germany, light motorcycles are not subject to registration (3 para. 2 no. 1c FZV) and thus also tax. They must bear a special registration number (Annex 4 Section 1 (1) FZV) and every two years for the main technical inspection.
When the light motorcycle was included in the Road Traffic Licensing Regulations (StVZO) in 1981, other requirements initially applied: The maximum capacity is 80 cm³, the maximum performance is 6000 rpm and the maximum speed is 80 km/h, which is expected to be safe and quiet. The current limit values have applied since 1996.
Anyone who holds either a driving licence in categories 1b or A1, which can be obtained from the age of 16, and holders of a driving licence in categories 3 or 4 are entitled to drive light motorcycles in Germany, provided this was obtained before 1 April 1980. Light motorcycles were also built by Simson, namely the types "Sperber", S70 and S83.

light motorcycle

idle nozzle

The idle nozzle is often referred to as an auxiliary nozzle (ND) and is considered an important carburetor component. As the name suggests, it is used for fuel mixture preparation in the idling system or in idle gas. Furthermore, it has a decisive influence on the partial load range and requires an optimum setting for smooth starting from idle throttle. In order to avoid so-called turning holes, the idle nozzle setting should be checked regularly. If the ND is too small or dirty, it can quickly lead to blockages and the motor dies. It is therefore important to ensure that cleaning is as consistent as possible. Too large idle nozzles are often responsible for the engine sinking at low revs. Depending on the load, it may not be possible to completely avoid replacement in certain cases, as the idle nozzle belongs to the wear part group.

handlebar spectacles

The handlebar goggle (also called fork bridge) is a part of the front wheel suspension ("fork") of two-wheeled vehicles. Handlebar goggles connect the two legs of the fork with its shaft, which is mounted in the steering head and can be rotated. The steering head is welded to the chassis of the two-wheeler. Their name comes from their slightly curved shape and the punched out holes that hold the forks, among other things. Motorized two-wheeled vehicles are usually equipped with two handlebar goggles, which increases the rigidity of the construction (i.e. its resistance to elastic deformation due to the action of forces or torques).

In Simson mopeds and motorcycles from MZ, handlebar goggles are mostly made of steel. They are wear-resistant, but should be checked for deformation or cracks after accidents and replaced if necessary.
handlebar spectacles

magnet-light ignition system

Magnet light ignition system 12 Volt > see also Vape A magnet light ignition system is basically a generator (Lima) with a contactless integrated fully electronic ignition. The system therefore supplies itself with electricity independently. However, there are different types of light magneto ignition. The early flywheel magneto ignition (SLMZ) with 6 volts was installed as standard in the Spatz SR4-1 PK and SR4-2SK, in the Star SR4-2 and 2/1, in the Schwalbe KR51/1 as well as in the Simson S50 N and B, among others. The capacitor (to minimize spark formation), breaker, ignition coil and two light coils are directly connected to the base plate and the ignition spark is generated by a mechanical breaker contact driven by the pole wheel cam. This very simple flying-light magneto ignition was replaced by the primary flying-light ignition (SLPZ) and later by the electronic flying-light ignition (SLEZ). The reliable VAPE magneto ignition systems are very popular for conversion to 12 V because they are largely maintenance-free. In addition, they have an enormously high performance potential. 12 V magneto ignition systems from Powerdynamo are also frequently used, for example for the MZ models ES, ETS and TS. However, magneto ignition systems with 6 volts are still available. For the exchange of the original electronic ignition or the Lima including ignition coil and interrupter a complete conversion set is worthwhile. Depending on the version, this includes the base plate, regulator and ignition coil, the flywheel and the matching cables. Optional sets with additional lamp assortment, flasher unit, plug and holding elements, horn and 12 V battery are also available. Of course you have to pay attention to the ABE for all modifications.

alternator

In motor vehicles - and thus also in motorised two-wheeled vehicles - an electric generator driven by the combustion engine is referred to as a generator. To transmit power from the engine to the alternator, most two-wheeled vehicles have the alternator directly coupled to the crankshaft. In the alternator, the mechanical energy (of the engine) is converted into electrical energy, which is supplied to the electrical devices of the motor vehicle. The electrical power is approximately proportional to the mechanical power: the more mechanical energy the motor produces, the more electrical energy it generates. To ensure that the power supply is not interrupted even when the vehicle's engine is running slowly or at a standstill, motor vehicles are equipped with a battery that stores energy.
The obsolete-sounding term "alternator" can be explained by the history of vehicle construction, in the early days of which the electric generator had the exclusive function of supplying the vehicle's headlight with electricity. An alternative name for the alternator is "dynamo".
Simson mopeds and MZ motorcycles also have alternators. These should be serviced together with the engine at regular intervals and after longer breaks (e.g. at the beginning of the season).

alternator

idler

The idler wheel is a component of the transmission of, among other things, motorized two-wheelers. It is used with Simson mopeds as well as with MZ motorcycles. Gearboxes are used for power transmission. The idler wheel is a component of the shift roller, which is used for shifting (changing gears) in sequential gearboxes. Sequential gearboxes are gearboxes where it is only possible to shift to the next lower or higher gear, but where it is not possible to skip gears. Sequential gears are used on motorcycles and a few other motor vehicles. The gearboxes of motor vehicles are usually gear drives in which the power is transmitted from the drive shaft via the layshaft to the output shaft, with the shafts meshing via gear wheels. One rotationally fixed gear wheel and one loosely connected to a shaft form a pair. The rotationally fixed wheel is called the fixed wheel, the loose wheel is called the loose wheel.
If the fixed wheel grips the idler wheel, the force is transferred from one shaft to the other. Idler wheels - like the gearbox as a whole - are oiled, but are otherwise maintenance-free.
idler

air filters

Air filters are devices for separating aerosol particles from the air, i.e. suspended particles such as sand or dust, which can lead to considerable wear in the engine. They are used in motor vehicles with petrol or diesel engines.
Depending on the model, Simson mopeds and MZ motorcycles are equipped with different types of filters (mainly oil and dry filters). Air filters are designed to transport a certain volume of air within a certain period of time. For this reason, the air filters should not be removed without replacement and only those filters should be used for tuning for which a similar intake volume was calculated as for the original filters.
Air filters become progressively dirty during driving, which increases the resistance of the intake air - with the result that the fuel-air mixture changes, negatively affecting the running of the engine. Air filters should therefore be cleaned at regular intervals, but at least once a year.

air filters

air filter cartridge

Air filter cartridges are installed in almost all mopeds, including the Simson mopeds. They consist of a metal frame, which contains a coconut fibre mesh or foam as filter material, which is framed on both sides by an air-permeable metal mesh. The filter material is oil-soaked. Air filters clean the intake air of suspended particles such as dust and sand, which could damage the engine. This is done by binding the suspended particles of the air flowing through the filter to the oil-soaked filter material. Air filters are designed in such a way that they always generate a certain intake pressure. However, the longer they are in use, the more dirty they become, which increases resistance to the intake air and reduces the intake pressure, so that less air reaches the carburettor. This changes the composition of the air-fuel mixture and makes the engine run less smoothly. Air filter cartridges should therefore be cleaned or replaced regularly.
air filter cartridge

engine mounts

The engine mount is a component that dampens the vibrations of the two-wheelers of the East German manufacturers MZ and Simson (but also of all other motor vehicles), which are caused by road unevenness and contact with resistances (such as when the wheel hits a kerbstone) while driving and which act on the engine from the chassis via the frame. Technically speaking, bearings allow movements in certain desired degrees of freedom and prevent them in certain undesired degrees of freedom. Engine mounts for Simson and MZ are mostly made of metal and rubber. They have not yet been fitted with modern hydromounts, i.e. bearing elements equipped with hydraulic damping. Engine mounts are functionally exposed to the effects of strong mechanical forces during the entire journey. They are therefore part of the wear parts of every motorised two-wheeler and should be checked as part of routine maintenance as well as whenever the engine is subject to noticeably strong vibrations.
engine mounts

hub

Hubs are machine elements that are pushed on shafts or axles on two-wheeled vehicles. While shafts serve not only to support the hub but also to transmit the rotary motion and torque, axles have a purely bearing function. Whether the two-wheeler has shaft-hub or axle-hub connections depends on whether it has front-wheel, rear-wheel or all-wheel drive.

Two-wheelers with rear wheel drives, for example, are equipped with an axle-hub connection at the front and a shaft-hub connection at the rear. MZ motorcycles and Simson mopeds usually have rear wheel drives. MZ and Simson two-wheel hubs are available as individual components or as part of complete wheels consisting of tyres, rims and hubs. In the case of hubs for Simson mopeds, there is also a choice between hubs with and without pre-mounted wheel bearings.

Hubs are wear parts that should be serviced at larger but regular intervals (about once a year or every 30,000 kilometres) and replaced as necessary. If the wheel bearing, which is particularly susceptible to wear, is not pre-mounted on the hub, it can also be replaced separately.
hub

needle nozzle

The needle nozzle is one of the components of the carburettor and is located in the upper nozzle block area. The needle nozzle system, which regulates the mixture composition especially at partial load, also includes partial load or nozzle needles. While the needle nozzle or nozzle holder normally cannot be adjusted, the nozzle needles are adjustable. A needle suspended higher by means of notches makes the mixture richer. The lower hanging needle ensures a leaner mixture.
Due to the pulsating gas flows, the needle nozzle wall can gradually increase in size. As a wear element, the needle nozzle must therefore be replaced in good time. It is essential to see the partial load needle and needle nozzle as a unit and to change both components at the same time.

standard parts

Standard parts are those components of motorised two-wheelers which are defined in a technical standard. Standards are issued by state institutions entrusted with the task of standardization, in Germany mainly by the Deutsches Institut für Normun (DIN). The aim of standardization is to standardize the objects described in the standard, thereby making them usable for a variety of applications and thus reducing manufacturing costs. The counterpart to the standard parts are the work parts manufactured by a particular manufacturer for use in its own products. Standard parts, on the other hand, are usually not produced in-house but purchased from specialist manufacturers. Typical standard parts used in motorised two-wheelers include bolts and nuts, springs and gaskets, cables and resistors.
Simson mopeds and MZ motorcycles are also equipped with numerous standard parts. A special feature is that these standard parts were standardised before 3 October 1990 according to the East German Technical Standards, Quality Regulations and Delivery Conditions (TGL), since then according to DIN. The transition from TGL to DIN was simplified by the fact that numerous TGLs complied with DIN standards in order to enable the GDR mechanical engineering companies to export wests.
standard parts

oil filter wrench

Oil filter wrenches are available in numerous designs. They allow the oil filter to be opened relatively easily and thus belong to the group of tool utensils for oil changes or similar maintenance work. While the so-called oil filter spiders are primarily suitable for cars, universal oil filter wrenches with steel straps are used for motorcycles and mopeds. They are infinitely adjustable and can therefore be used for almost all MZ or Simson models. So you do not have to pay attention to the oil filter size in general. In addition, the oil filter wrench replaces the complicated procedure with a screwdriver. There are also comparable versions with fabric tape. However, these are less robust than the steel or metal strip types.

connecting rod

The connecting rod, often referred to briefly as the connecting rod, connects the piston to the crankshaft. In the interaction of piston, connecting rod and crankshaft, the linear up and down movement of the piston is converted into the radial rotary movement of the crankshaft.

The connecting rod is equipped with a connecting rod eye at the upper and lower end. The lower eye sits on the crankpin of the crankshaft, the piston pin sits in the upper eye. There is no wear on the connecting rod itself, but the bearings in the connecting rod eyes wear out over time. The hobby screwdriver is unlikely to have the necessary pressing tools to replace the connecting rod bearings. All that remains is the way to the specialist workshop. Today, the plain bearings made of steel bronze used in the past are usually replaced by modern and durable needle roller bearings during an overhaul.
connecting rod

Flywheel - Flywheel

The pole wheel is a part of the ignition system and alternator of motorised two-wheelers. It is located above the so-called base plate, on which an ignition coil and two light coils (for headlights and rear light) are mounted. The pole wheel is connected to the crankshaft via a disk spring also known as a "half moon wedge".
The main function of the pole wheel is to create a magnetic field that generates voltage in the three coils mounted on the base plate. Magnets are embedded in the outer ring of the pole wheel for this purpose, whereby the positive and negative poles are alternately arranged next to each other, so that an alternating magnetic field is created. If this is led past the wires of the three coils, a voltage is induced in them. By connecting them to the pole wheel, the first time the crankshaft is turned (as happens when starting), the pole wheel is rotated and a voltage is induced. Since no external energy source (battery, rechargeable battery) is required to start this process, it is also referred to as "self-induction". The second function of the pole wheel is to actuate the interrupter, which switches the ignition on at the optimum ignition point and then off again.
Pole wheels are used in Simson mopeds and MZ motorcycles and are largely maintenance-free. However, care should be taken that the pole wheel does not run out of shape - which can happen, for example, if the crankshaft is distorted.

Flywheel - Flywheel

polar wheel puller

The pole wheel puller is a relatively simple special tool for removing the pole wheel from the crankshaft journal.
The polar wheel is very heavy. This mass must be accelerated and decelerated at the change of speed. The tungsten carbide spring in the groove of the crankshaft journal could not withstand the occurring forces and is only used for precise guidance. The frictional connection between crankshaft and pole wheel is produced by a conical press fit. After tightening, the nut serves only as a safety device against loose vibration.
To separate the pole wheel from the crankshaft again a pole wheel puller is necessary. After loosening the nut, it is screwed into the 26 mm internal thread of the pole wheel. A screw with conical tip presses on the crankshaft end and pulls the pole wheel off the journal.
Even if there are some hair-raising alternative methods with pinched screwdrivers or heating with burners and light hammer blows circulating on the Internet, there is no alternative to the right polewheel puller without the danger of serious damage to the crankshaft or its bearings.


polar wheel puller

primary coil

The primary coil is mounted on the base plate of some Simson mopeds. Like this it is a part of the ignition system. The base plate is a round metal plate on which various components belonging to the ignition system are mounted. Which components are installed on the base plate depends on which base plate model it is. During the production period of the Simson mopeds in GDR times, three main types of base plates were produced: Those with magnetos, those with primary igniters and those with electronic igniters. While in the classic breaker ignition (with magneto ignition) the ignition coil, two light coils, the breaker and the capacitor are located on the base plate, in the base plate with primary coil the primary coil has taken the place of the ignition coil, which in turn is located as an external component outside the base plate and is supplied with current by the primary coil. With Simson mopeds, the primary coil should be checked at the latest during scheduled maintenance of the entire ignition system.
primary coil

wheel bearing

The wheel bearings are located between the wheel hub and the axle. There are always two bearings per wheel. They ensure that the wheel can turn easily and without play on the axle. All Simson and MZ models are equipped with ball bearings. Even if the wheel bearings last quite long, they still belong to the wear parts.

To check the wheel bearings, the moped is jacked up on the main stand and the corresponding wheel is unloaded. Then you grab the wheel by the tire and try to move it crosswise to the running direction. No play should be detectable. Since the wheel bearings in the hub fit tightly, replacement is not so easy. Experienced screwdrivers carefully (!) heat the wheel hub and cool the new wheel bearings in the freezer or with cold spray. Anyone who works here with brute force will very quickly damage the bearing surface of the aluminium hub when hitting it.
wheel bearing

Frame - Frame beam

The mostly powder-coated frame beam protects the engine and other components on the one hand and stabilizes the entire frame construction on the other. In many cases, the beams are already welded to the footrest supports. On the Simson Enduro S51E, the frame beam is standard and is simply referred to as the Enduro strut. The opinions in the biker scene differ regarding the appearance, but in terms of practical suitability these aspirations make sense. If you want to build a frame beam yourself, you should definitely consider the brackets, i.e. the approx. 4 mm thick weld-on brackets or the gusset plate (for example for S50, S51 and S70) for fastening. There are also precisely fitting covers for the beams for Simson models.

regeneration

Regeneration is the comprehensive maintenance and care of important components of a motor vehicle - in particular the engine, the cylinder, the pistons and crankshafts as well as the tank. Regenerations of the corresponding components are also offered for Simson and MZ two-wheelers. During regeneration, the respective component is dismantled into its individual components, which are then cleaned and replaced if necessary. During regeneration, not only worn accessories are replaced, but also those parts whose wear is to be expected at regular intervals (such as sealing rings).
Regenerations are usually offered in service packages at a fixed price. Services that exceed the respective offer are usually charged separately - for example, if the cleaning effort is particularly high or if previously undiscovered major damage is only detected during regeneration. Regeneration can significantly extend the life of engines and cylinders, pistons and crankshafts, as well as the tanks of older two-wheelers, and increase their performance.
regeneration

rotor

The rotor is a rotating component of the alternator and is also called the pole or flywheel. It has built-in magnets with north and south poles and revolves around the immobile stator with copper wire windings. The drive is via the crankshaft or the belt and thus a three-phase alternating voltage is obtained. The conversion into direct current is carried out by controllers and rectifiers. In addition to the rotor with electromagnet, there are rotors as permanent magnets. These are mostly installed in the Simson moped, whereby the efficiency of permanent magnet generators is rather limited. However, advantages can be found in the simple design and reliability. If magnetic force is lost, however, the rotor with permanent magnet should be replaced. VAPE rotors are significantly more heat-resistant, especially at high speeds, and optionally have a mounting device for the fan wheel. For a VAPE ignition system, there are also complete conversion set versions with all relevant accessories and detailed instructions.

shifting claw

In gearboxes with claw gears, the shift claw ensures the frictional connection between the individual gear pairs of the corresponding gear. Gear wheels that are not connected to the selector shaft in a rotationally fixed manner are shifted transversely to the direction of rotation. The shifting claws engage and thus ensure the transmission of power between the gear pairs of the selected gear. Optically one can imagine the shift claws also like the loopholes of a round, medieval watchtower, which are attached laterally to the gear wheel and engage into a suitable counterpart.
However, the term shift claw is also commonly used for various other components of the circuit, which resemble a claw optically, but are actually called shift fork, shift piece or actuating claw.
shifting claw

shift roller

A shift roller, which enables the gears of sequential gearboxes to be shifted, can be found in Simson mopeds and MZ motorcycles with claw gears. So-called grooved tracks are milled into the shifting roller, which are responsible for the axial shifting of the shifting claws or forks. If the switching roller has to be replaced due to wear on the cam tracks, it is essential to ensure that there is no or only absolutely minimal axial play. It is therefore important that the switching roller is precisely balanced with the corresponding thrust washer. An appropriate compensating washer usually helps against too much axial clearance. In addition, the circlips and the pin for the shift roller should fit exactly or be optimally matched to each other.

selector shaft

The shift shaft is part of the gearbox. It is necessary for the change and the selection of the individual gears. The Simson and MZ gearboxes have very different designs.

On MZ motorcycles the selector shaft is a straight, smooth shaft. At the outer end, the footswitch lever sits on a toothing. Inside the transmission, a shift piece moves a cam roller, which engages and locks the corresponding gear.

The Simson mopeds are equipped with a draw wedge gear. Here a wedge is moved by means of a grooved shift shaft during gear change and the corresponding gear wheel is locked. Here the foot pedal is not located directly on the shift shaft. The movement of the shift lever is transmitted to the selector shaft via a mechanism in the clutch housing.
selector shaft

rocker switch

In the case of two-wheelers, a rocker switch is a special type of foot pedal. Models with normal footrests have almost no shift paddles. To engage a higher gear, the foot is simply moved under the gear lever and a movement in the ankle causes the tension to push the gear lever upwards. However, this foot movement is not possible on models with running boards, where you would have to lift the whole foot to move the gear lever upwards. Therefore, the gear lever with two arms in the form of a rocker is installed here.
For example, the rear arm of the seesaw is operated with the heel to shift up. With Simson and MZ the Schwalbe is the only model which was delivered as standard with shift paddle.
rocker switch

headlights

Colloquially, the complete front lamp of a two-wheeler is often referred to as a headlight. The actual headlight is therefore also referred to as the headlight insert.

It consists of a reflector and a glass diffusing lens. The reflector serves as a holder for the Bilux lamp and the parking light bulb. It bundles the light. The diffusing lens breaks the bundled light and distributes it. This ensures good illumination of the road without dazzling oncoming traffic more than necessary.
headlights

headlight housing

The headlight ring is available in as many different versions as there are headlights. On some models, such as the Simson bird mopeds or the MZ ES/2 models, the headlight ring is just a plastic cover that hides the headlight insert holder. On other models, the headlamp insert is fixed in the headlamp ring and connected to the housing. On other models, the headlight ring connects the headlight insert to the lamp housing like a cranked hose clip.
headlight housing

headlight ring

The headlight housings at Simson and MZ are very different. On the Schwalbe, for example, the headlight housing is part of the fairing. It is similar with the ES - models of MZ and the remaining bird series of Simson (all models with front wheel swing arm), where tank and lamp form an optical unit.
On the models with telescopic fork, the headlight housing is a lamp pot. Depending on the model and series, the headlight housing also houses the ignition lock and, in some cases, the speedometer.
headlight ring

calliper

Somewhat more known is the calliper, possibly as a calliper or as a caliber. A steel calliper for motorcycles and mopeds made by MZ and Simson normally consists of a flat rod with millimetre scale, two measuring legs and a movable calliper. If reading the scale is too complicated for you, or if you need measurement results not only in millimetres, but also in inches or in 0.01 mm increments, you should opt for a battery-powered digital caliper with display. This also allows you to set 0 positions and display plus/minus values. A caliper gauge is used to determine, among other things, the sizes of springs and screws as well as distances and fits accurate to the millimetre.

mud flaps

The mud flaps are riveted to the rear ends of the mudguards. As the name suggests, they are designed to absorb dirt and moisture from the wheels.
In the GDR the moped was often the only motorized means of transport. It had to be used daily and in all weathers. At the front mudguard the mud flap protects the moped and the driver. At the rear fender the following traffic. The newer mud flaps are made of relatively soft plastic. Older models were often fitted with so-called rubber spraying tabs.

heat-shrink tubing

The heat shrink tubing is a tubing made of thermoplastics which shrinks due to the influence of supplied heat (hot air blow dryer, lighter). It is mainly used for repair work on Simson and MZ electrics. With a shrinkage rate of 2:1 and a shrinkage temperature of approx. 120 ºC, it is used, for example, to insulate bare cables. After shrinking, the hose is also temperature-resistant and also offers particularly reliable corrosion protection. Shrink tubing is available in different lengths and with different wall thicknesses. If you want to carry out extensive insulation work on your motorcycle or moped electrics, a complete set is a good idea.

float

The float with its two float chambers belongs to the components of the carburettor and is responsible for the regulated fuel supply and for a constant filling level in the carburettor pan. The gasoline first takes the path from the tank container through the gasoline hose, then flows into the carburetor, then passes the open float needle valve and reaches the tub. The float itself lies (floats) on top and ensures that the valve closes in time when the optimum fuel quantity is reached. A functioning float thus prevents too high a water level and flooding. In general, Simson floats are very robust, but cracks in the float chambers can still occur. In this case, the component loses its buoyancy, submerges and no longer closes the valve. Often a defective float valve needle is also responsible for problems when starting. If the float has to be replaced, you should pay attention to the exact height. In the BVF 15N1-5 carburettor it is 28 mm when closed and 32 mm when open. A Simson with BVF 16N1-12 requires a closed height of 29 mm and an open height of 33.5 mm. The position of the generally very sensitive float needle, on the other hand, can be optimised, whereby the modified insertion of the needle into the plate requires a high degree of dexterity as well as a little specialist knowledge.

swing arm

The swingarm connects the rigid frame of the motorcycle with the axle of the rear wheel. With the MZ - ES models also a pushed swingarm works at the front wheel.

The swingarm has a supporting function in the chassis. The swingarm is used in conjunction with the suspension struts to compensate for uneven road surfaces. The swing arm is mounted on the frame in the swing axle and can be moved up and down across the direction of travel. The wheel axle and the chain tensioner guide are located in the rear slot of the swingarm.

The rocker arm itself is not subject to wear. Even the swingarm bearing on the suspension on the frame should last a moped's life in most cases.
swing arm

Flywheel - Flywheel

Simmering

soffitte

The name Soffitte is mainly based on the cylindrical design. In order to use this lamp, the lamp base must also meet the appropriate requirements, as the tubular lamp has a contact device at each end. In the case of two-wheeled vehicles, tubular lamps with a glow wire are occasionally still found in tail lights and license plate lights and more frequently in turn signals. In this case they are often offered as a set including turn signal caps. According to the StVZO, however, there are strong approval restrictions. Soffits which do not serve exclusively as interior lighting are not permitted without the K test mark or ECE.

cotter pin

Optically, the sapwood resembles a standard hairpin. It serves as a fastening and securing element for Simson, MZ and IWL mopeds, scooters and motorcycles. The simple and thus double-sided straight one-way split pin is particularly easy to remove, but must not be reused afterwards. A cotter pin has one straight and one wavy side. Although it is usually more difficult to remove, it can be used several times and is predestined for particularly safety-relevant applications. Split pins are used, among other things, for the brake block holder, for the steel tilting stand, for bearing bolts on the foot brake lever, for securing screw connections and for shift rods. Although the sapwood is actually a comparatively inconspicuous element and in some exceptional cases even the question of sense or nonsense is asked, it has an important meaning at least from a legal point of view. If the splint securing device is entered in the ABE, it will also be given decisive consideration during the main inspection. One should therefore consider very carefully whether the exchange of a split pin, for example against a self-locking mother, is a good idea. Of course you should always pay attention to the exact measurements. For MZ and Simson, split pins are available individually or as a complete range of split pins in the box for frequent screwdrivers.

plug coupling

A plug-in coupling for the fuel hose is often referred to as a quick-release coupling or disconnector and is usually made of plastic. It closes on both sides and therefore has corresponding plug connections at both ends. During repair work on the moped or motorcycle, the plug coupling automatically seals or closes the fuel line. This effectively prevents an unwanted outflow of petrol. However, it is essential to pay attention to the internal and external connection dimensions. Most Simson petrol hoses have an inside diameter of 4.7 mm or 6.2 mm and an outside diameter of 7.3 or 8.8 mm. In a well sorted tool stock the plug coupling should not be missing at all.

plug-in base lamp

The plug-in base lamp is not screwed in, but plugged in. That explains her name. In contrast to the glass bulb, which is very thin and therefore relatively sensitive, the pins are largely robust. As a combined instrument with BAX10s base for Simson SR 50X and 80X as well as for the SRA 25 and SRA 50, they serve as speedometer lamps with 1.2 watts and 12 volts. Transparent LED plug-in base lamps often have an E-test mark, but this is not mandatory. This type of lamp is also used as dashboard lighting in other motor vehicles. However, it should be noted that many plug-in base lamps are not suitable as soon as an on-board computer monitors the incandescent lamps. In this case, malfunctions or interruptions can occur quickly.

control unit

he control unit is part of an electronic ignition system. It adjusts the ignition timing to the engine speed.

A certain time passes between the triggering of the ignition pulse at the ignition coil and the actual spark at the spark plug. It is therefore necessary to interrupt the charging current of the ignition coil a little earlier (ignition pulse) than the ignition spark should ignite the gasoline - air mixture in the combustion chamber. The following problem exists. The time delay of the ignition coil is due to the design and is always the same. However, the speed of the motor changes. With conventional breaker ignition systems, the ignition timing "moves" with it. The higher the speed, the later the ignition takes place. At a certain speed, there is no longer optimum combustion and the engine produces less power.
In electronic ignition systems, the control unit ensures that the ignition timing follows the engine speed and is always ignited at the optimum time over the entire speed range.
control unit

push rod

The pushrod is part of the chassis assembly and is primarily used to transmit the force between the so-called pushrod and the rocker arm bridge. It therefore opens and closes the motor valves. The ends of the rod are rounded to fit directly into the ball socket of the tappet or rocker arm. Simson has installed pushrods mainly in the AWO tours and AWO sport. The EMW was also equipped with it. The advantage of the pushrods with corresponding thrust pieces is the low maintenance. In general, this technology is considered obsolete, but is always defended by connoisseurs due to its reliability. However, pushrods are only conditionally suitable for high speeds.

StVO - Road traffic regulations

Legal basis for behaviour in road traffic. Includes regulations for drivers of motorised vehicles as well as for pedestrians and cyclists.

StVZO - Road Traffic Licensing Regulations

Regulates the formal and technical requirements for the registration of vehicles. It is divided into three parts:

1. registration of vehicles in general
2. type-approval and component type-approval
3. construction and operating rules

part-load needle

The partial load needle is an important component in the slide carburettor. It is mounted in the round slide (on very early AWO models also in the flat slide) and sits with its tapered tip in the main nozzle. In the partial load range, i.e. every gas position between idling and full throttle, the partial load needle is lifted together with the round slide and, due to its conical shape, releases an ever-increasing cross-section in the main nozzle. This ensures that, depending on the gas position, the required amount of petrol is also carried along by the air flow in the intake duct. At the upper end, several notches are worked into the partial load needle, with the help of which it is attached to the needle holding plate.
These notches can be used to adjust the height in relation to the gas slide. In this way the enrichment of the gasoline - air mixture can be adjusted. If you hang the needle higher, the mixture becomes richer, if you hang the needle lower, the mixture becomes leaner. The partial load needle is a wear part and is incorporated into the main nozzle over time. Needle and nozzle should always be replaced together.
part-load needle

telescopic fork

The correct professional term for telescopic fork is actually telescopic fork. Two telescope-like tubes, guided into each other, form a fork leg. Two of these fork legs, often called fork spars, guide the front wheel and also act as shock absorbers.
Each fork leg consists of a standpipe and an immersion tube. The immersion tube is often referred to as the sliding tube. The standpipe is fixed in the fork bridge. Inside the standpipe there is a helical compression spring, which serves as a suspension spring, as well as the damper tube and the damper piston. The standpipe and immersion tube are sealed against each other by means of a shaft seal ring (Simmerring). Filling it with fork oil creates a hydraulic shock absorber.
The two fork legs are connected to the steering head of the frame via the triple clamp and the steering tube. The handlebar is mounted on the upper fork goggle and between the two immersion tubes the axle carries the front wheel.

telescopic fork

cup spring

The disc spring actually has its name from the visual similarity to a deep plate. The spring force results from the compression of the material in the inner area. The decisive advantage of disc springs is their low overall height compared to the diameter. This makes disc springs particularly suitable as clutch springs for two-wheelers. The disc spring presses the clutch discs together and thus creates a frictional connection between the crankshaft and the gearbox. By relieving the spring when the clutch lever is actuated, the clutch separates.
With the MZ and AWO hitches, disc springs are also used on the steering head for vibration damping.
cup spring

TG - Parts certificate

Contains a list of vehicles for which the part is suitable. An officially recognised expert must inspect the extension/conversion and then issue an inspection certificate. Without this acceptance certificate, the operating permit expires.

disconnecting device

If it is necessary to separate the two engine halves of a Simson or MZ * for overhauling the crankshaft or the gearbox, a separating device is required. The crankshaft bearing and the bearing of the output shaft are fixed both on the shafts and in the housing. This means that the housing halves cannot be easily separated from each other even after all connecting screws have been loosened. A separating device functions according to the principle of a puller. Several screws are screwed through a pressure plate into the thread of the housing half. Two further threaded holes are positioned so that the tip of the pressure screws presses on the crankshaft journal or on the output shaft. By tightening the pressure screws evenly and step by step, the half of the housing is removed without damaging the material. Although instructions for separating the motor housing without special tools also circulate on the Internet, this usually causes considerable damage and finally ruins the motor.

* This is about the standard models from DDR production. The AWO's and some post turn models have different engines.
disconnecting device

TÜV - Technical Inspection Association

Is a registered association that carries out safety inspections as a technical testing organization according to state laws or regulations. The best known is the general inspection of motor vehicles.

nameplate

The nameplate is a small aluminium plate riveted to the frame on which some important information about the vehicle is printed or embossed. On the type plates of Simson and MZ the manufacturer is printed on top. There are four fields below, on which the model designation, the year of manufacture, the permissible total weight and the chassis number are noted. At the very bottom you often find the remark "Made in the GDR" or "Made in German Democratic Republic". Different texts can be found depending on the manufacturer and year of manufacture. On some type plates there is also the number 1 in a triangle with rounded corners. This is a quality seal of the GDR and corresponds to "quality class 1". This seal was awarded to products that qualitatively corresponded to the average of the world market.
nameplate

interrupter

The breaker (actually: breaker contact) is an electrical contact that opens and closes a circuit at regular intervals. Depending on the application, interrupters are available in a variety of designs. They are also installed in motorised two-wheelers, including Simson mopeds and MZ motorcycles, where the breaker is located on the base plate and is an important component of the primary and magneto flywheel ignition. At the ignition point, the breaker opens and interrupts the current flow of the primary coil, conducting the electrical energy to the ignition coil. This results in high voltage, which leads to the generation of an ignition spark that ignites the compressed fuel mixture in the cylinder. The breaker is opened and closed by a slight elevation on the pole wheel.
In motorised two-wheeled vehicles such as Simson mopeds and MZ motorcycles, the interrupters are wear parts and must therefore be replaced regularly. An exchange becomes necessary if the specified distance between the contact plates can no longer be achieved even by readjustment when the breaker is open.
interrupter

ape

VAPE from the Czech Republic specializes in the production of ignition and control systems as well as voltage regulators and alternators for motorcycles. When Simson and MZ talk about Vape, they are usually talking about a particularly powerful 12-volt ignition system. It was originally installed in the S53 and S83. Since the Vape is almost maintenance-free, countless mopeds are now being converted to VAPE 12 V. The VAPE is a very powerful and reliable moped. One of the few weaknesses of a Vape ignition, however, is the regulator. The latter can say goodbye in the worst case. In addition, the magnets could also detach from the pole wheel. The Vape system scores with an extra high reliability and with a clearly better light output. The Vape conversion of a 6 volt contact ignition in older MZ models is also extremely advantageous from today's point of view. 70-3 with 100 watts is absolutely sufficient for the equipment with H4 as well as the 70-5 with 110 watts. For retrofitting a Simson S50, S51, S70, KR 51/1 and 51/2 (Schwalbe), SR4-4 (Habicht) or SR4-2 (Star), for example, a complete retrofit kit with or without horn, battery and light source is recommended. Of course, individual components are also available. By the way, this also includes the somewhat susceptible controller. For the conversion you should bring very good knowledge in the field of electrics and never start without exact instructions and wiring diagram. For less experienced hobbyists the way to an expert workshop is worthwhile in any case.

carburetor

The carburettor of a Simson moped (for example BVF 16N1-11 for S 51 and S 70) is positioned on the cylinder by means of a carburettor flange connection. It provides for an optimal fuel-air mixture, is thus responsible for the fuel supply as well as for the fine distribution and/or atomization. Since the cylinder can become very hot, there is a gasket on the flange that protects against false air and heat. The main components of the carburettor are the venturi tube (air flow, at the narrowest point = vacuum generation), the nozzle needle (adjustable): higher = richer mixture, lower = leaner mixture), the needle nozzle or main nozzle (not adjustable), the idle nozzle or auxiliary nozzle (mixture preparation in idle mode), the slider (movable by throttle cable), the throttle cap (controls the air flow), the float (regulates the fuel supply) and the choke (starting aid by richer petrol mixture). The carburettor with all its components should be cleaned intensively, especially after the winter time. It is dismantled into its individual parts and checked for signs of wear, blocked nozzles and porous seals if necessary. The consistent replacement of defective parts can also replace major repairs in many cases. Only in the rarest cases the carburettor of MZ - and Simson two-wheelers must be changed completely.

carburetor pan

The carburetor tub is also known as the float housing. Together with the float and the float needle valve, it serves as a supply and discharge element, for regulation and control. If there is no constant level in the tub or if the housing is flooded, there is often a defect in the float. Before the repair, the carburetor pan is unscrewed. Some of the older Simson models from the early 70s were fitted with carburettor tubs which could be screwed on from below and which were somewhat easier to remove. When replacing or after cleaning the carburettor, make sure that the seal is evenly applied. This should also be replaced if necessary. It is also important that the carburetor pan and gaskets are exactly matched to the respective carburetor, because a float housing for the MZ ETZ 125 and 150 does not fit on the carburetor of a Simson Star SRA 25/50.

four-stroke engine

Four-stroke engines are combustion engines used in motor vehicles, including MZ motorcycles and Simson mopeds. Put simply, four-stroke engines compress the fuel-air mixture and then burn it, whereby the combustion process is triggered by external ignition (via the spark plug). A characteristic feature of four-stroke engines is that they are equipped with inlet and outlet valves which regulate the inflow of the unburned fuel-air mixture and the escape of the exhaust gases and enable precise timing of the work processes. A characteristic feature of the four-stroke engine is that a working cycle consists of four piston strokes, each piston stroke corresponding to one working cycle: intake (1st cycle), compression (2nd cycle), working (3rd cycle) and ejection (4th cycle).

The advantages of the four-stroke engine include relatively low fuel consumption due to the more precise timing and its higher torque. For motorised two-wheelers, four-stroke engines are used almost exclusively for larger machines with a cubic capacity of approx. 500 cm³ or more, including numerous MZ motorcycles.

full acceptance

This occurs when the vehicle registration certificate for a vehicle has expired. A full inspection must also be carried out if vehicles were imported into Germany from abroad. This also applies to mopeds if they were not previously registered on the territory of the former GDR!

trademark badge

Trademark badges for the Simson bird series, such as for the swallow, the star, the hawk, the sparrowhawk and the sparrowhawk, can be recognized by the red flash on a white background. Directly above is the originally designed lettering "Simson" and completes the well-known logo. These plaques made of aluminium are available in gold or silver. They can be attached optimally to the handlebar shell by inserting the metal strips into the shell openings and then bending them over. So that the badge does not come off again after a short time, the handlebar shell should be thoroughly cleaned and dried beforehand. Thus the unmistakable logo becomes an absolute eye-catcher for every East Algerian and faithful Simson fan.

white wall tyre

The first tires were all white. They are made of natural rubber and white is the natural colour of this material. To make the tires more durable, more and more additives were added to the natural rubber in the course of development to ensure a black color. However, these additives were very expensive and were therefore only used on the treads of the tyres for the time being. This is how the whitewall tyres were created for economic reasons. At that time, completely black tires were much more expensive and were considered noble. Today white wall tires are only used for optical reasons. The material is the same, it is only dyed white.
Even though neither Simson nor MZ ever offered models with white wall tires, they are very popular with enthusiasts today. Especially with the Schwalbe and the ES models of the first generation white wall tires underline the oldtimer optics.
white wall tyre

shaft sealing ring

In colloquial terms, radial shaft seals are also referred to as Simmerrings. However, this name is only a registered trademark, whose name goes back to the inventor Walther Simmer.
Shaft sealing rings are used wherever a rotating shaft leaves a housing and this transition must be sealed. The shaft sealing ring is firmly seated in the housing and its sealing lips ensure that the shaft is sealed. The sealing lips are pressed onto the shaft surface by a hose spring (worm spring). For motorcycles with telescopic forks, shaft seals are also used to seal the upper shaft of the immersion tube towards the standpipe.
shaft sealing ring

draw spline shaft

A drawing spline shaft is a component of certain types of gearbox used on some motorised two-wheelers (in particular light motorcycles), including the Simson mopeds. Spline shafts are characterized by the fact that the positive connection to the hub of a shaft-hub connection is made by drivers with straight and parallel flanks - in contrast to spline shafts, where the flanks of the drivers are involute. The number of carriers depends on the number of gears of the respective operation. With the drawing wedge shaft, the gears are engaged and disengaged by the so-called drawing wedge. It is inserted via a milled window into the internally drilled drawing wedge shaft, where it is moved by a rod. Depending on the position of the drawing wedge, the gears are positively connected to the drawing wedge shaft.
Due to the permanent engagement and disengagement of the gears, as is usual in normal driving operation, drawing spline shafts wear out and must therefore be replaced if there is too much "play" during the shifting process and the gears can no longer be engaged without problems.
draw spline shaft

tie rod

In engine technology, a tie rod is a relatively long type of stud bolt used to connect the engine casing, cylinder and cylinder head. In the Simson and MZ two-wheelers, apart from the rather rare four-strokes, the tie rods are long bolts with rolled threads at each end. Stud bolts are used in motor construction whenever the sensitive threads in the motor housing must be protected from damage. Motor housings are usually made of cast aluminium. Aluminium is a rather soft material. Screws and bolts, on the other hand, are made of steel, which is much harder. In addition, contact corrosion often occurs between the different materials. As a rule, a stud bolt is screwed into the cast aluminium only once during initial assembly and only has to be loosened on the opposite side to replace the fixed components. If a screw were used in the same place, there would always be the danger of ruining the thread in the expensive motor housing. When working on the tie rods, the prescribed tightening torque must be carefully observed, as with all other stud bolts.
tie rod

ignition system

In combustion engines, the ignition system is the device for igniting the fuel-air mixture in the cylinder combustion chamber. Ignition systems can be found in all motor vehicles.
In the Simson mopeds and MZ motorcycles equipped with gasoline engines, ignition takes place by generating an ignition spark that ignites the fuel-air mixture. There are - depending on type and model - different procedures for this. The ignition systems used in Simson mopeds and MZ motorcycles are mainly magnetic and electronic ignition systems.
Magneto ignitions do not require an electrical energy storage device (such as a battery or rechargeable batteries) to trigger the ignition process, because the electrical energy required to generate the ignition spark is generated by an electrical generator driven by the combustion engine. Until the 1960s, magneto ignition was the standard ignition for motor vehicles, but since then it has gradually been replaced by electronic ignition systems, which were also used in Simson mopeds and MZ motorcycles of recent years.
Electronic ignition systems have an electronic control unit instead of the breaker installed in magneto ignition systems, which calculates the ignition timing and triggers the ignition by sending an electronic signal. The breakers of magneto ignition systems wear out and must be replaced from time to time. The electronic control parts of electronic control systems, on the other hand, are not susceptible to wear.


ignition system

spark plug connectors

The spark plug connector, colloquially also called spark plug connector, establishes the high-voltage connection between the ignition cable and the spark plug. In addition to the electrical connection via a mechanical spring terminal, the spark plug connector also has an interference suppression function.
Simson and MZ use spark plug connectors with 1 kilo-ohm interference suppression resistor. Although interference suppression is not necessary for the function, uninterrupted ignition systems cause interference in radio reception in the immediate vicinity.
spark plug connectors

ignition contact

The ignition contact is often also called breaker contact, ignition interrupter or simply breaker. It is a mechanical switch which is opened by a cam once per crankshaft revolution. When opened, the ignition contact interrupts the voltage at the primary winding of the ignition coil and thus triggers the ignition spark.
The ignition contact is located on the breaker plate. The unit can be rotated axially through oblong holes in this plate. This makes it possible to set the correct ignition timing.

The ignition contact is a wearing part. On the one hand, the electrical contact surface burns off in the course of time, on the other hand the actuating hammer on the cam ring wears off. In modern engines, the mechanical breaker has long been replaced by contactless Hall sensors and an electronic ignition system.


ignition contact

ignition switch

The two-wheelers of Simson and MZ were equipped with so-called ignition light switches. Since the corresponding keys were standard models, they hardly served the purpose of theft protection. Only the lock in the steering head was responsible for this.
The ignition light switch fulfils several tasks. Depending on the position of the "ignition key" either only the ignition is on, or the ignition plus parking light or the ignition plus the complete lighting system. A further position only switches on the parking light, whereby the ignition key can be removed.

With the models of the ES and TS series from MZ there is still a special position in the ignition switch. Here, in simple terms, the electromechanical regulator is bridged and the alternator current is fed directly to the ignition system. So these models could, in the case of a discharged or defective battery, be pushed quite simply.


ignition switch

ignition lock

A real ignition lock, as one is used to from a car or from western motorcycles, did not exist at Simson and MZ, at least in the GDR. Only with some models after the "Wende" an ignition lock was installed, which also deserves the name lock.
The GDR models had an "ignition light switch", which was also operated with a kind of key, but this "key" was a standard model and could be bought by everyone for a few pfennigs. A narrow screwdriver or the mailbox key on the key ring has, with a little "fumbling" this function also fulfilled.

ignition coil

The ignition coil works according to the principle of magnetic induction and is responsible for generating the high-voltage pulse which then triggers the spark at the spark plug. This high voltage pulse is achieved by two different windings which are wound around a common iron core within the ignition coil.

The different wire thicknesses and number of turns of the primary and secondary windings ensure the transformation of the battery voltage into the high-voltage range. The winding ratio is between 1:150 and 1:200, depending on the ignition coil type. The normal operating voltage is applied in the primary coil. A strong magnetic field builds up around the iron core and the primary coil. If this voltage is switched off by the lower cup or an electronic ignition module, this magnetic field collapses and a high voltage is induced in the secondary coil by the field change, which triggers the decisive ignition spark.
ignition coil

ignition timing

The ignition time is usually not the time at which the spark of the spark plug actually starts the combustion process in the combustion chamber, but the time at which this process is triggered by the interrupter or the transmitter of the ignition electronics. Since a few milliseconds elapse between the time of triggering and the time of ignition of the compressed petrol/air mixture, irrespective of the engine speed, the ignition time must be set shortly before the top dead centre of the piston is reached. The delay in the ignition coil is about one millisecond. The time between the ignition of the combustion and the maximum extent of the explosion in the combustion chamber, another two to three milliseconds. The optimum ignition time is therefore directly before the upper dead center (OT) is reached. The mixture is maximally compressed and spreads with maximum effect after exceeding the OT.
The correct ignition timing is given either in ° (degrees) of the crankshaft position before TDC, or in millimetres of the piston before TDC. The optimum ignition timing varies depending on the model and depends on the rated speed and ignition type.
ignition timing

two-stroke engine

Two-stroke engines are internal combustion engines in which a fuel-air mixture is first compressed and then burned, whereby combustion is initiated by a positive ignition (via the spark plug). Two-stroke engines are used in motor vehicles, including Simson mopeds and MZ motorcycles. The design of two-stroke engines is very simple, as they essentially consist only of the crankshaft with connecting rod and piston and the cylinder (with the inlet and outlet slots for the fuel-air mixture). A characteristic feature of two-stroke engines is that a working cycle consists of two piston strokes. If the piston moves upwards (1st cycle, compression/suction), a negative pressure is created in the crankcase. The fuel-air mixture flows into the crankcase via the inlet port, which is also released. Meanwhile, the piston compresses the fuel-air mixture in the working cylinder, which is finally ignited by the ignition spark of the spark plug near the top dead centre. Due to the pressure generated during the combustion of the gas, the piston is driven downwards again (2nd cycle, operation/pre-compression). This closes the inlet channel and at the same time pre-compresses the mixture in the crankcase. In the area of the lower dead centre, the piston opens the outlet channel so that the burnt gases (exhaust gases) can escape. The advantages of the two-stroke engine include low manufacturing costs due to its simple design, low wear due to the few moving parts, and high engine speeds. Two-stroke engines are the most widely used type of engine for mopeds, such as the Simson mopeds.
two-stroke engine

top hat

The cylinder is a cylindrical chamber (working chamber) in which the piston movements take place. The lower end is in the crankcase and the cylinder head (cylinder cover) is on top. At Simson, cast iron with lamellar graphite (relatively low expansion at high temperatures) was used for production. The slots incorporated in the cylinder liner (optionally two or four channels) serve as outlets and inlets (mixture supply into the combustion chamber - exhaust gases from the combustion chamber) as well as overflowers. The cylinder is cooled in the shrink-wrapped aluminium heat sink by means of a blower on older motorcycles or by means of an airstream. Apart from the BK 350 with two-cylinder boxer engine, various prototypes, sports versions or own conversions, Simson and MZ mopeds and motorcycles usually have only one cylinder. The calculation of the cubic capacity in cm³ is made up of the piston stroke travel and the diameter of the cylinder liner. Cylinders are wear parts. If the cylinder is to be ground (fine boring and honing), special expertise and above all special tools are at the top of the bidding list. If it is necessary to replace the cylinder if defects cannot be corrected, we recommend replacing the cylinder including head, piston, cylinder stud and piston rings. However, cylinders without cylinder liners and pistons are also available. First and foremost with tuning cylinders, StVO specifications must be observed as always.

cylinder head

In single-cylinder two-stroke engines, the cylinder head is not a complicated component. It forms the upper part of the combustion chamber and consists essentially of a cast part with cooling fins, four holes for the tie rods and a threaded hole for the spark plug.
In four-stroke engines, on the other hand, the valves and their drive are housed in the cylinder head. The intake and exhaust ports of the four-stroke engine also pass through the cylinder head. Although the designation is the same, the two-stroke engine is rather a "simple cover", while the four-stroke engine is a complex component with many components.
cylinder head

cylindrical roller

Cylindrical rollers are rolling elements - i.e. rotational elements made of a hard material (such as steel) - which, as elements of a linear rolling guide or a rolling bearing, reduce the friction that occurs between the various components of the bearing or guide.
Rolling bearings are bearings in which rolling bodies (such as cylindrical rollers) located between an inner ring and an outer ring reduce the frictional resistance - and thus assume the function of lubrication in so-called plain bearings. Rolling bearings are used for shafts and axles. Linear roller guides, on the other hand, are used to translate (shift) one or more machine assemblies as smoothly as possible while simultaneously maintaining the (linear) direction of motion.
In rolling bearings and some linear rolling guides, the individual rolling elements - such as cylindrical rollers - are always kept at the same distance from each other by a cage. Cylindrical rollers are also used in Simson mopeds and MZ motorcycles, including in the crankshaft and rocker bearings.

cylindrical roller

dowel pin

Cylindrical pins are aids for connecting two workpieces. They are also used on motorised two-wheelers, including Simson's mopeds and MZ's motorcycles.
In general, pins connect components in the radial direction (of the pins) in a form-fit manner by inserting them through holes which pass through all the components to be connected. The pin is prevented from falling out of the bore by frictional locking. As the name suggests, cylindrical pins are cylindrical and usually have rounded or chamfered (i.e. bevelled) edges. Pins of this type are used for position-securing connections that rarely or never have to be loosened.
Cylindrical pins are used in Simson mopeds and MZ motorcycles in very different areas, for example in the engine, carburetor and float.

dowel pin