Customer service
Puch Maxi E50 clutch explained: function, adjustment and clutch housing play
The Puch Maxi E50 uses an automatic centrifugal clutch. That means the moped does not have a manual gearbox: as the engine speed rises, the clutch shoes move outward, grip the clutch housing and transfer power to the secondary shaft and front sprocket.
A good E50 clutch setup is not only about choosing the right clutch. The clutch housing, plain bearing, shim rings, clutch oil, spring tension and clutch type all need to work together. If one of these parts is worn or incorrectly adjusted, your Puch can slip too much, engage too early, make noise, wear the sprockets or feel weak when pulling away.
How does a Puch Maxi E50 clutch work?
The E50 clutch is a wet centrifugal clutch. When the engine is idling, the clutch shoes sit inward and the moped stays still. As the engine revs increase, centrifugal force pushes the clutch shoes outward. When the shoes touch the inside of the clutch housing, the clutch begins to transfer power.
The clutch housing rotates around the crankshaft and drives the secondary shaft. The front sprocket is mounted on the secondary shaft, which then sends power to the rear wheel through the chain. Between the clutch housing and crankshaft sits a plain bearing or bronze bushing. This bearing is very important because it allows the clutch housing to rotate smoothly.
The E50 clutch usually contains the following main parts:
- Clutch base plate
- Clutch shoes or clutch segments
- Clutch springs
- Spring adjustment screws
- Clutch housing
- Plain bearing or bronze bushing
- Shim rings and circlip
Pedal-start and kickstart Puch E50 clutch types
There are two main E50 clutch versions: the pedal-start clutch and the kickstart clutch. The correct version depends on the engine type.
| Clutch type | How to recognise it | Used on | Important note |
|---|---|---|---|
| Pedal-start clutch | Has friction lining on the back of the clutch base plate | Pedal-start Puch Maxi E50 engines | The pressure plate pushes against the lining to turn the crankshaft during starting. |
| Kickstart clutch | No friction lining on the back of the clutch plate | Kickstart E50 engines | The kickstart mechanism drives the crankshaft through a pinion instead of using the rear clutch lining. |
| 2-shoe clutch | Two clutch segments | Often found on older Maxi S or Maxi N models | Common on older standard setups. |
| 3-shoe clutch | Three clutch segments | Many later E50 engines and replacement clutches | Offers more contact area inside the clutch housing. |
Always check whether your engine is pedal-start or kickstart before ordering a clutch, clutch housing or pressure plate. The parts may look similar, but the starting system changes what the clutch needs to do.
Back to topClutch housing play, plain bearings and shim rings
Many E50 clutch problems come from play in the clutch housing. Even with a rebuilt engine, a new clutch housing or a new crankshaft, there can still be movement if the plain bearing, shim rings or clutch housing position are not correct.
The clutch housing should rotate smoothly on the crankshaft. If it moves too much from side to side or in and out, the sprocket behind the clutch housing can be loaded incorrectly. This can cause wear on the large sprocket, the small clutch sprocket or both. It can also create a bad rattling or grinding noise from the clutch side of the engine.
What should you check?
| Check | Good condition | Problem sign | Possible solution |
|---|---|---|---|
| Plain bearing / bushing | Housing turns smoothly with almost no visible play | Housing rocks or moves visibly | Replace the plain bearing or upgrade to a better bushing. |
| Axial play | Movement can be felt slightly, but not clearly seen | Housing moves in and out visibly | Use the correct shim rings to remove excess movement. |
| Radial play | Very small movement only | Housing can be wiggled noticeably on the crankshaft | Inspect the bushing, housing and crankshaft surface. |
| Clutch housing position | Housing runs freely without touching the clutch | Housing rubs against reinforcement plate or clutch parts | Move the housing with shim rings until it runs freely. |
| Circlip / Seeger ring | Fully seated in the groove | Missing, damaged or not seated correctly | Replace or refit before running the engine. |
You can find E50 clutch parts, clutch housings and related parts in the Puch Maxi E50 clutch parts category. For shim rings, pressure plates, bushings and small mounting parts, see the Puch clutch accessories category.
Back to topHow do you adjust a Puch E50 clutch?
A Puch E50 clutch is adjusted by changing the spring preload with the adjustment screws. Screwing the adjustment screws in increases spring tension. Unscrewing the adjustment screws reduces spring tension. This changes how much the clutch slips and when the clutch segments begin to drive the clutch housing.
With more spring tension, the clutch shoes need more engine speed before they can move outward and grip the clutch housing. This makes the clutch engage later. Because the engine side and clutch housing side have a greater speed difference, especially when pulling away from a standstill, the clutch slips more before both parts reach the same speed.
| Goal | Adjustment screw direction | Spring setting | What happens | When it helps |
|---|---|---|---|---|
| More slip | Screw the adjustment screws in further | Spring tension increases | The clutch engages later. The clutch shoes need more rpm before they can grip the housing, creating more speed difference and more slip before the clutch and housing reach the same speed. | Often useful on faster or higher-revving setups that need to leave from a higher rpm range. |
| Less slip | Unscrew the adjustment screws further | Spring tension decreases | The clutch engages earlier. The shoes move outward sooner, the speed difference is smaller, and the clutch connects more directly with less slip. | Often useful on original or mild setups that need clean, direct engagement without excessive clutch heat. |
| Equal shoe adjustment | Set every adjustment screw the same amount | All clutch segments are balanced | All clutch shoes engage the clutch housing evenly. | Important for every clutch setup. Uneven adjustment can make the clutch grab, chatter or feel inconsistent. |
Basic adjustment method
A good basic setting is to make sure all spring adjustment screws are set evenly. On many replacement clutches, the screws can be set approximately flush with the clutch shoe surface as a starting point. Another common starting point is to screw the adjusters in and then turn them back out around 1.5 turns. After that, the clutch must be tested on the road.
Do not expect the clutch to be perfect on the first try. A good adjustment often takes several test rides. On a tuned or race setup, the clutch may need to come out multiple times before it feels right.
Standard, reinforced and custom Puch E50 clutches
The best clutch depends on the power level of your setup. A standard 25 km/h or 45 km/h Puch engine does not need the same clutch as a tuned 50cc, 70cc or high-rpm setup.
| Setup | Recommended clutch type | Why | Extra parts to consider |
|---|---|---|---|
| Standard 25 km/h or 45 km/h E50 | Standard replacement clutch | Enough grip and durability for original power levels | Fresh clutch oil, good bushing, correct shim rings |
| Fast 50cc setup | Better lining material or suitable clutch springs | The engine may need a more controlled engagement depending on its rpm range | Careful spring and screw adjustment |
| 70cc street setup | Reinforced clutch or Aramid-style clutch | More torque can bend pins or wear standard shoes quickly | Reinforcement plate, shim ring set, improved clutch housing support |
| High-power or race setup | Custom reinforced clutch | Higher rpm, heat and grip demands need stronger parts | Reinforced clutch housing, better bushing or needle bearing, performance clutch oil |
Clutch springs
Clutch springs and adjustment screws determine how the clutch segments move outward and grip the clutch housing. On an adjustable Puch E50 clutch, screwing the adjustment screws in further increases spring tension. The clutch shoes then need more rpm before they can overcome the spring tension, so the clutch engages later and slips more before the clutch and housing reach the same speed.
Unscrewing the adjustment screws further reduces spring tension. The clutch shoes can move outward sooner, so the clutch engages earlier and slips less. This creates a more direct engagement, but it may not always suit a tuned engine that needs to leave from a higher rpm range.
Different spring types can change the available adjustment range, but stronger parts are not automatically better. A standard engine usually needs a clean, direct engagement. A faster or higher-revving setup may need more controlled slip so the engine can stay in the useful part of its power range.
Reinforcement rings and reinforcement plates
On tuned engines, the clutch shoes and the small pins they pivot on are exposed to much higher forces. A reinforcement ring or reinforcement plate connects and supports these areas so they are less likely to bend. This is especially useful on 70cc and high-torque setups.
Custom clutch housings
A modified clutch is often used together with an improved clutch housing. Upgraded clutch housings can use stronger materials, improved plain bearings, better bronze bushings or needle bearings. These parts help the housing survive higher rpm and reduce wear compared with old original parts.
Clutch oil
The E50 clutch runs in oil. Regular oil changes help reduce wear. For high-rpm or tuned setups, better clutch oil can help deal with the extra heat created by clutch slip. If the oil is old, dirty or overheated, the clutch may behave inconsistently.
Back to topPuchShop clutch videos
The videos below show the clutch housing play, bushing replacement, shim ring setup and clutch adjustment process in more detail.
Puch E50 clutch housing play and shim rings
Puch E50 clutch assembly and adjustment
FAQ: Puch Maxi E50 clutch adjustment
How do I know if my Puch E50 clutch housing has too much play?
If the clutch housing moves visibly from side to side or in and out, there is too much play. A tiny amount of movement that can be felt but not clearly seen is usually normal. Visible play should be checked because it can cause noise and sprocket wear.
Should I replace the plain bearing when fitting a clutch housing?
Yes, it is usually smart to replace the plain bearing or bushing if there is play, noise or visible wear. A fresh bushing often removes most of the clutch housing play and helps the housing rotate smoothly.
Which way do I turn the Puch E50 clutch screws for more slip?
For more slip, screw the adjustment screws in further. This increases spring tension, makes the clutch engage later and creates more slip before the clutch and housing reach the same speed.
Which way do I turn the Puch E50 clutch screws for less slip?
For less slip, unscrew the adjustment screws further. This reduces spring tension, makes the clutch engage earlier and creates a more direct engagement with less slip.
Do stronger clutch springs make my Puch faster?
Stronger springs do not directly create more engine power. They change the clutch engagement moment. More spring tension makes the clutch engage later and slip more, which can help a tuned engine leave from a higher rpm range, but too much slip creates heat and wear.
How many times do I need to adjust the clutch?
It often takes more than one attempt. A clutch is usually adjusted by testing, removing it, making a small change and testing again. Standard engines may only need a small adjustment, while tuned or race setups can take several tries.
Should a new clutch be soaked in oil before assembly?
For first assembly, it is recommended to let the clutch sit in clutch oil before installation so the friction material can absorb oil. This helps protect the clutch during the first start and first test ride.
