chain keeps coming off when starting.

the_edge150

Dealer
Aug 21, 2008
289
0
0
Monrovia,CA
ok i got a new happy-time 50CC kit, built it (took 3 days) and now every time i go to start it, the chain comes off the drive sprocket. any ideas??
 

ebmvegan

New Member
Jul 15, 2008
283
0
0
OC, Ca
Check to see if the chain rolls onto the sprocket easily. The pitch or roller diameter or with could be off. Or the drive sprocket and wheel sprocket could be misaligned. Also check the tension of the chain.
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
235
63
up north now
Too much tension.
The roller/tensioner is out of alignment (sometimes you have to twist the metal a bit if your chainstays are angled.)
Engine out of alignment with rear sprocket.
 

the_edge150

Dealer
Aug 21, 2008
289
0
0
Monrovia,CA
i loosened it up and its working a bit better,and i mounted the tensioner onto the plate where the coaster brake arm goes, so its riding pfine now, thanks for helping