My '98 ZX9R will "jerk" under hard acceleration in first and second gear. In third gear and up, it runs like a scolded dog. I have had worn clutches several times in my years of riding and this isn't your normal worn clutch slipping. It feels very similar to the chain jumping teeth on the sprocket causing it to jerk. I've also had that happen before due to a loose chain, but that made a very noticable noise. The problem I have now makes no noise, and my acceleration is "jerky", not a smooth slip like worn clutches.
My clutches and steels are new, the oil level is fine, the oil is brand new, the motor is flawless, but I don't know what to try next. If anyone has some experience with this problem, please let me know what you did to fix it, or least let me know what was causing the problem.

Thank you.

 

Welcome to the forums....

My first guess would have been the chain or clutch...But you ruled that out. Maybe rear hub damper? I think I remember someone having this prob once b4, and I believe it was the engine mounts. Been a while tho and I have a bad memory....lol

I can't help ya much , but I bet someone can. Hang out and enjoy your stay

 

Thanks BIGRIG, I've just about exhausted all possibilties that would be a reasonable cause. I'm ready to start trying those wild ideas and hopefully I might stumble onto something.

Anyone else have an idea, something I can check?

 

No prob man...... Have you tried to readjust the clutch?

 

I have tried loosening the clutch springs, tightening the clutch springs, tightening the chain, replacing the clutches with new ones twice, drained the oil, tried thinner oil then thicker oil, installed new steels, put a laser temp on the header and all cylinders are hitting, new spark plugs-the old ones looked fine. Some of these are long shots I know but, what else can I do?

Still, a rough slip through first and second. It seems as though first and second gear put enough torque on the drive train to cause the problem, but after shifting to third, it never does it. Higher gears pull a little less so the problem doesn't occur. I have completly ruled out that maybe its a miss in the motor for a couple reasons. The motor runs great in 3rd and up, and the slip feels nothing like a short cut out. If it was a miss, I think I would hear it in my revs, but I don't.

I'm reaching the end of my patience, and you don't even wanna know what the dealership said. They just want me to bring it in. Someone help please.

 

holy crap man. You have exhausted all possiblities....lol.

man, somebody somewhere had to have had this prob.... GL man..

 

Very weird! My Kawasaki Ninja 500R just started doing this as well. I hopped on this forum to see if this is a common thing...dont know what to do about it, but it's driving me crazy, and i'm afraid that if I keep riding it, it's going to cause some serious damage. Literally EXACT same problem...if anyone can help it'll be two times appreciated!

 

I am thinking on the same lines of the cush drive as BR mentioned. I had something similar happen on my ZX7. The cush drive got hard and allowed excess slop.

 

I haven't checked the cush drive yet? I can't picture how the cush drive would cause this problem, but, if you say its happened to you before then I"ll take your word for it. I'm heading out to check that out and I'll let you guys know what it looks like.

Thanks for all the help so far you guys.

 

I wonder if maybe there are a couple of teeth off of your first gear making it jerk like that. I mean it could be the problem i don't know if this helps you out at all or not.