When it’s time to do some maintenance on your 4-stroke motorized bicycle, make sure you have this 49cc Transmission Drive Chain Sprocket Shaft on hand. This gear fits inside of the transmission of a 4-cycle bike engine to help pull the internal drive chain needed to move the bike, so when it’s damaged you’re left without a running motor.
If your 4 stroke engine revs but won’t move, there’s something wrong with the transmission, and it’s likely something with this shaft.
The Transmission Chain Gear is made for the majority of 4-cycle motorized bikes with chain-driven transmissions out there, including 5G Flying Horse and most Huasheng motorized bicycle engine kits. Do yourself a favor and have a spare 4-Stroke Transmission Chain Gear handy for vital repairs and maintenance.

This shaft is located within the transfer case of our Flying Horse 5G 4-Stroke 49cc bicycle engine kits, and is what the transfer case chain runs on.