blowing out of second into first. (92 quadracer lt250r)

[screamin-eagle]

I just picked up a quadracer for a price i couldn't refuse. I rode it easy and it was fine but when i started screamin it up in second gear it popped out and went to first. Any idea's? Or anything to try so we can pin point the problem a little better? Let me know any thoughts
Thanks

[screamin-eagle]

Any idea's a all? I guess im just going to have to rip it apart and see what im into then order the parts

[Qracer]

Bent shift fork or shift fork rails, worn engagement dogs on the gears & worn shift drum. These are the most common problems I have seen.