Index
Overview
Tuning
Tuning Overview
Lighter Roller Weights
Remove Variator Restrictor
Stiffer Clutch Springs
Move Needle Jet Washer
Increase Fuel Jet Size
Carb De-restriction
Un-Restricted CDI Unit
Un-Restricted Air Inlet
Trouble Shooting
Compression Test
Fuel Enricher Test
Seized Brake Caliper
General Maintenance
Replace Air Filter
Check & Change Oil
Spark Plug Change
Idle Speed Adjust
Change Brake Pads
Adjust Valve Lash
Electrical
Testing the Battery & Charging System
Battery Change
Coil Change
HT Lead Change
Transmission
Remove Starter Motor
Refurb Bendix Gear
Engine
Camshaft Removal
Valve Removal
Replace Valve Guides
Engine Removal
Return to Transport Listings
Models Covered
Lexmoto, Pulse, Sukida, Baotion, Lifan, Direct Bikes, Huatian, JMStar, QT50, LF50QT, YH50QT,
BT49qt, 139 QMB, Honda, GY6, Motorbike, Taishan, Jonway, Peugeot V-Clic, QT-4, QT-7, QT-9, qt-11, QT-50
Kymco, Tank, Quinqzi, PGO, Roketa, Strada, Vento, Yamati, QMB139, SunL, SYM, QingQi, Volano Plus Many More Chinese Motorcycles, mopeds and
scooters!
Roller Weights Overview
The roller weights are located in your Chinese Scooters variator. This is in the transmission of
your scooter and they effectively determine when your scooter will change gear. All 4 stoke scooters with variable transmission, not just chinese
import clones of the honda GY6 QMB139, will have Roller Weights in the Transmission. They can also be found in small motorbikes and motorcycles
with a CVT, not just scooters.
Steps to Change a Scooters Roller Weights
Applies to: Baotian, Sukida, Hoatian, Lifan, JMStar, Jinlun, Kymco, Tank, Quinqzi, PGO, Roketa, Strada and Taishan QingQi and many more...
Changing Your Roller Weights
The roller weights in your chinese import scooters transmission directly effect the gearing of your scooter. As the variator spins faster, centrifugal force pushes the weights outwards which in turn closes the variator
cones, increasing the gear ratio. The centifugal force is countered by springs and as the revs of the engine decrease, these springs force the roller weights in your scooter back, lowering the gear ratio.
In short, most Chinese import scooters are fitted with very heavy roller weights which gives poor acceleration and hill climbing ability. Just changing them for lighter roller weights can have a dramatic
effect on your scooters performance, particularily if you are quite heavy.
- Remove the Kick Start lever.
- Undo the bolts that secure the transmission cover and remove the cover and its gasket.
- Undo the nut that secures the drive pulley onto the end of the crankshaft. This nut is tight, you will either have to devise a tool to stop the crankshaft from turning whilst you undo the nut, or ideally, use an air impact wrench.
- Remove the pulley, belt and sleeve taking carefull note of the order in which the parts are removed.
TIP: You may see a spacer on the drive pulley sleeve. If so this is a restrictor designed to stop the scooter reaching top gear! You may remove this restrictor.
- Your scooters roller weights can be found in the back of the inner drive pulley. You may have to remove three screws and a plate to gain access.
- Remove the weights and weight one of them to determine their weight. I have found that 7.5 gram roller weights work quite well, my scooter came with 12 gram weights! Way too heavy.
- Refitting is the reverse procedure. I personaly would fit heavier duty clutch springs whilst I have the cover off the transmission.
Notes
Take care when removing the transmission cover from your GY6 Chinese clone scooter, the kick start mechanism is fiddly and may come off the cover when you remove it.
The crankshaft bolt can be hard to undo as the engine just wants to turn. The best solution is to use an impact wrench, like those used by tyre fitters. You can purchase fairly cheap electric impact wrenches these days that should do the job. Alternately, get a helper to hold the rear brake on whilst you turn the nut with your wrench.