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Clutch Problem

Started by BarkG, October 13, 2001, 05:24:34 PM

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BarkG

I need help!  I recently rebuilt my CBR900RR engine and everything went fine, started up ok and runs good.  I installed a brand new Barnett clutch with new Plates, Frictions, and Honda OEM springs.  When I test rode it giving the engine some heat cycles I got on the gas a little hard but not to hard and what I thought was the rear wheel spinning was actually the clutch.  I can do a very modest roll-on and the engine lacks power because the clutch is spinning.  My question is, is there any break-in time for a new clutch?  Also there is new Honda 10W40 oil (non-syn).  Clutch cable is adjusted properly.  Any ideas would be greatly appreciated!

ysr612

#1
I have done a few clutches but never ran into that problem.  
are they kevlar and if yes did you soak them first.

one other thing did you make sure you put the same number in as you took out and the odd one nearest the motor.

BarkG

Thanks for the reply.  Yes they are Kevlar and I did soak them before assembly.

ysr612

I added an edit not that I am that great of mechanic

Sage

do you have free play in the clutch cable? did you tighten the spring bolts down all the way?

BarkG

Yes, the cable has the correct amount of free play and the springs are tightened down.  I put the Honda OEM clutch back in and in ran perfectly.  I am assuming that by using the Barnett clutch with the Honda spings and not Barnett's heavy duty springs is causing it to spin.  What do you think?

Sage

it should work ok with the honda springs? measure the honda clutch pack vs. the barnett and see if the overall thickness of the barnett is thinner, this will cause slip.

Eric Kelcher

Barnett seems to be lacking something in QC lately the clutch pack I recieved last year was over 1.5mm thinner than used but not worn out stock pack. Then this year I order springs and the barnett was 4 mm shorter than wear limit.  ???  I would try ordering the stock clutches.
Eric Kelcher
ASRA/CCS Director of Competition

vfrracer

I had the same problem with a EBC clutch and then I put my stock one back in and all was good.  What cured my problem was to rum the EBC clutch with the EBC spriings.  Not a hint of a slip after that.  I put in an RC30 race clutch and man what a lever pull after that.  My forearm was sore after a day of riding.  But now I am used to it and it is no big deal.  Hope this helps.

Jim Eglinger

GKing

I had the same problem with a Barnett a few years ago and contacted them.  The first thing they asked was the height of the clutch pack.  Thought it was a stock thing.  Sent it back and they added a thicker plate which then worked.  

I spoke with an old time (not old-timer) motorcycle drag racing tuner and builder and he said the stock clutch plates are almost bullet proof.  He didn't see any advantage of the aftermarkets over stock.

Super Dave

I'll agree that the stock stuff is pretty good.  But advertising has done Barnett well.

Regardless, we had a problem similar to this with kevlar clutches several years ago.  You put it in, adjust it, ride in, and it all comes apart as it gets warm.

Kevlar clutches MUST be adjusted when warm.  Seems as though they change how they work over a heat range.  

Still check everything over, but it might be easy to try and adjust it warm and see whay happens.  I would bet that Barnett will recommend this also.
Super Dave

Jay

There should be a secondary clutch adjustment that will fix the problem. Most Barrnett problems are the opposite, with the friction plates being too thick. check a service manual, and see if there is another adjustment, it should be a lock nut with a screw or an allen slot in the middle. Look inline with the clutch on both sides of the bike.