Clutch oddness?

[musicman]

So I recently rebuilt my clutch, back to original, using OE parts from Randy, refurbished steels. Is there a break-in period for the clutch? I've got about 150-200 miles on it now, and today I gave her the reigns and let it run for a while. Nearing redline it did something I've never felt anything do before, it started "skipping", for lack of more intelligent words. Like the clutch couldn't hold. But I've never known a clutch to behave like that, it was very very VERY brief "pops" where RPM increased and I could feel the bike fall back. I've only had it happen a few times now, and it didn't do it before I replaced the clutch. The cushioning spring is still in there, no wire, running Lucas 20-50 motorcycle oil, non-syn.

I'm also wondering if it could be something else entirely, the skipping is so brief that I may be mistaken about the RPM increasing, it doesn't always do it, but when it does it's nearing redline. Could it possibly be ignition? This thing doesn't have points (I hope!), so that kind of makes me lean away from the theory.

[FJmonkey]

What year FJ do you have? That sounds just the dreaded 2nd gear issue. My 86' when pushed will act like a rev limiter. But just in 2nd gear. So, All gears or just 2nd?

[racerman_27410]

what gear was this happening in?


its also possible you could be bouncing off the rev limiter.... i believe the FJ tach reads kind of slow.


Kookaloo!

[ribbert]

So I recently rebuilt my clutch, back to original, using OE parts from Randy, refurbished steels. Is there a break-in period for the clutch? I've got about 150-200 miles on it now, and today I gave her the reigns and let it run for a while. Nearing redline it did something I've never felt anything do before, it started "skipping", for lack of more intelligent words. Like the clutch couldn't hold. But I've never known a clutch to behave like that, it was very very VERY brief "pops" where RPM increased and I could feel the bike fall back. I've only had it happen a few times now, and it didn't do it before I replaced the clutch. The cushioning spring is still in there, no wire, running Lucas 20-50 motorcycle oil, non-syn.

I'm also wondering if it could be something else entirely, the skipping is so brief that I may be mistaken about the RPM increasing, it doesn't always do it, but when it does it's nearing redline. Could it possibly be ignition? This thing doesn't have points (I hope!), so that kind of makes me lean away from the theory.

Depending on your diagnostic skills and terminology, what you describe is the opposite of an ignition problem, which would be a miss.

I have had a situation which fits your description perfectly.  In the higher gears (higher speed) nearing redline ( max power )  on a bumpy road, the crap rear shocker can't keep the wheel on the ground firmly enough to maintain drive and the momentry loss of traction gives those little blips of revs several times a second.

Your new clutch is also now allowing the motor to send max power to the wheel, which, if it was slipping before it couldn't have and would explain why it's only happening since you did the clutch.

Bit of long shot but try it out on a smooth road.

Can't hurt and it's a good excuse to ring it out through the gears.

They reckon MotoGP bikes loose 10% of their power down the main straight the same way.

My tyre won't spin up even in 1st on a wet road at WOT but it will at 140kh + in 4th or 5th in the wet for the same reason. This has scared the shit out me on several occasions while overtaking.

Noel

[musicman]

I think you called it with the back shock, I've never had a clutch behave in a way like this before, so it makes me lean away from it, and the more I sit back and think about it, just doesn't seem like it can be ignition. I wish I could put it in text better what it's doing. Where I wind the bike up is a back-country road, and it's relatively smooth but does have it's share of bumps. I don't think it's 2nd gear, my last pull it did it on, I looked down as fast I could and looked at the wrong gauge, lol, meant to look at the tach but instead I saw I was running around 120mph, I'm sure I was in 3rd not 2nd. I also wondered if the chain or front sprocket could be suspect, I've been meaning for months to take the 5 minutes and tighten the chain but I never remember to do it when I'm in the garage, always hop on and THEN think "hey, you need to tighten that dummy... do it when you get home" So heck the chain could be skipping for all I know. It's stored for the fall/winter now though, guess I'll find out more come spring.