Clutch Slipping or Gearbox Issue? - R75/5

[boxertwinjeff]

So I'm riding along in top gear say 100kph, and twist the throttle open real quick, and the clutch appears to slip
until I back off slightly. Could this have anything to do with my 4 speed box?
remembering it has a 1000cc Powerkit, and a New Clutch Plate which was installed at the same time
3 years ago, as the old plate could'nt handle the increased Torque. The gearbox does have a slight whine to it.
Cheers Jeff.

[Ken in Oklahoma]

So I'm riding along in top gear say 100kph, and twist the throttle open real quick, and the clutch appears to slip
until I back off slightly. Could this have anything to do with my 4 speed box?
remembering it has a 1000cc Powerkit, and a New Clutch Plate which was installed at the same time
3 years ago, as the old plate could'nt handle the increased Torque. The gearbox does have a slight whine to it.

The symptoms, slipping in high gear under a lot of throttle, are classic symptoms for a slipping clutch. The fact that a new clutch plate was recently installed doesn't matter. You may need something other than just a new disk. The pressure plate comes to mind, as in a weak diaphragm spring. The slippage happens at the maximum torque RPM and 100kph would be about right for that.

As for the slight whine, I'm not so sure about the 4 speeds, but I reckon that like the 5 speed transmissions only the high gear utilizes helical gears (no whine at the cost of slightly higher power loss). The lower gears are spur gears and the "whine" is the sound of the gear teeth "impacting" each other. In the 5 speed transmissions some of the lower gears seem noisier than the others.

Ken

[Kurt in S.A.]

Be sure that the clutch cable is adjusted properly.

Kurt in S.A.

[Major Softie]

A clutch disc of incorrect thickness (too thin) could also cause this to happen, even with a new clutch and everything else being correct.

[Duane Ausherman]

After you check the suggestions listed above, then prepare to bite the bullet, you need to open it up for a full inspection. My site shows the measurements needed for the clutch to work.

We can't hear your whine, so it is impossible for us to tell you that it is normal, or a symptom of a problem. Lets hope not, as it can get expensive inside there.

[boxertwinjeff]

Thanks for your responses, if I remember correctly a heavier duty clutch spring from an R100 was installed
with the New Clutch plate,...yes, looks like an Internal inspection. Will any damage occur if I keep riding it
for the time being, as long as I don't thrash it?...as I'm focused on getting the R90S road legal at the moment.

[Duane Ausherman]

Yes, any slipping is burning the friction plate. Just don't go fast enough to allow it to slip. The other potential damage is if the two steel plates weren't replaced and are warped, then they will accelerate damage to the friction disc.

You also need to consider pulling the flywheel and oil pump cover. Inspect the input shaft for a seal leak.

[Jean]

Just so we completely understand, you ARE seeing the tach RPM increase without an increase in road speed...as an indication the clutch is slipping?
Otherwise, what suggests slippage?

[boxertwinjeff]

Wasnt staring down at, neither glancing at the Tacho the few ocassions this has happened,... did hear & feel it though.