hi i have a 125cc loncin/lifan engine fitted to a go kart, timing chain snapped from starting it in gear, got a replacement fitted it. buggy started and ran like a clock ran it in gear while on a stand once on the ground put into gear went about 10 metres and snapped the timing chain again while running. has anybody got any ideas!!! dont want to go through the whole process again just to have it snap again.

 

All I can think of is worn sprockets, the camshaft seizing or a problem with the chain guides. The cam may free off once cool so inspect the journals.

 

What did the automatic cam chain adjuster look like? (its a block that rubs against the timing chain to keep the slack out of it as it wears)