Transmission / Gearbox tranny you have to remove the

you have to remove the four screws that hold the transmission housing on to the engine

the pressure ratings on the sidewall of Chinese mini dirt bike tires are incorrect

This will usually be 15-20 psi

Sometimes the spring in the clutch breaks

Transmission / Gearbox tranny you have to remove theTransmission, or gear box for 40cc 4 stroke motors. Comes with the stock 11 tooth pinion gear attached. Typical symptoms that indicate a gearbox: Your bike started making a terrible rattling noise in the engine. Rear wheel is locked up, when pulling on the pull start the back wheel immediately starts spinning. To replace the gearbox, you have to remove the four screws that hold the transmission housing on to the engine. Use an 8mm socket wrench to