HELP chain problems!!!

[csr250r]

Hey i got my R fixed and i took it out yesterday and it snapped a chain,(red one from ebay) then today i put on an old one off my blaster and i didnt even gun it or anything and i barely got 200yards from the house... it did this before and it broke my case saver today, im running a 12 tooth sprocket in front and 38 in rear, are these too small or isnt it alligned right or what els could it be???

[86 Quad R]

what shape are the sprockets and chain(free from kinking) in? have ya verified that the alignment is ok? is the chain adjusted properly? is the swinger sitting in the quad square?

[redrooster310r]

check axle bearings....sounds like an alignment prob..... and too tight on the chain.....got a skid plate? sometimes too loose on a chain will flick off.

[pdxbigfoot]

And the motor is shifting under power throwing the whole alighment with the front and rear sprockets off.Its a recipe for disaster!!