Also my first post. Also wanna say great site!
I actually signed up just for the same problem that you are having.
I have an '03 YZ250 and as soon as I get into 5th gear is starts jerking. It's gotta be a motor problem, not tranny. Everyone I have talked to so far says it's either electrical or intake. If anyone knows, please reply.
Thanks for any help fellow 2-strokers!