chain keeps coming off

[nismo]

on my 250x my chain keeps coming off and its tight and well oiled, but i cant figure out why it keeps coming off. As soon as i start to go 3 rd gear or faster it comes off. do i need a new sporket or is it bent? Any ideas would help.
thanks

[300exTJjeeper]

Seems to me that something is bent, then again I could be wrong.

My best bet would be to jack up the rear end and start it up and have someone put it in 1st gear and run it real slow and look at the back.

This what I would do, I have never had a chain fall off, but I am new to riding too, so I would start there

[4TraxRider]

Are your bearings bad enough to allow enough free play to pop the chain? I agree with jeeper. Put it ona stand and see if you can find the problem.

[wilkin250r]

I agree, it sounds like either the rear sprocket is bent, or mis-aligned.

Prop the back end and spin the tires. If you need, you can start the quad, jack the back end up, and then put it in gear. You want it spinning fast enough to detect any wobble in the rear sprocket.

If there is no wobble, check to make sure the front and rear sprockets are lined up properly.

[nismo]

thanks i think i need new swing arm bearings(i am working on it today and getting the parts i need)

[seven]

I would bet that it is a bent Chain. If one of your links on your chain is tweeked a little your chain will pop off under hard exceleration. I had this happen on my R.

[KandK952]

also check the teeth on the sprockets. my rear sprocket got worn down and kept popping. it popped like 3 times before i figured it out.