TOPIC:

When I upshift from 1st to 2nd the bike down shifts back to neutral. If I upshift from 2nd to third real quick it will hold the gear. I took the crankcase cover off and removed the clutch plates and everything looks okay in the gearshift mech. Any ideas? Thanks.

Noticed nobody's jumped in here, so I'll put in my two cents worth, and maybe somebody who knows something will correct me.
I don't know how familiar you are with your motorcycle's insides. So if I seem to be talking down to you, forgive me. By the same token, if I use too big a word, holler. It's an adiction of mine!
Your transmission's gear teeth are always meshed together. That's why a motorcycle transmission is called "constant mesh". However, they have what engineers call dogs cut into their sides, and there are other "nongears" that have matching dogs,that slide along on splines on the transmission shafts. Actually, if it was me I'd call them side gear teeth, but them anal engineers say that in order to be a gear tooth it has to be shaped a special way. So, here is a link to an animation that shows you what I'm talking about:
transmission animation
So, the teeth on the edges of the transmission are always engaged, but the teeth on the sides of the gears engage and disengage, as the gears are slid along the shafts, pushed back and forth by metal fingers, called (no, not "shifting fingers"), shift forks.
What has probably happened is that somebody missed second gear way too many times and the second gear dogs are rounded off. Bad news. If this is true, you need new gears. Or a different bike.
Sorry, man.

Post edited by: pstrbrc, at: 2007/03/18 13:57

What he said. You could replace them for cheap if you have the know how or guts.