Busa Clutch slipping...starting to run out of ideas.




TheDude27

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2003 Hayabusa 20000K miles.

Problem: Under heavy load (>6K RPM 3gear or higher) I'm getting clutch slippage. Clutch is stock

So far I have:

- Oil change Mobil 4T
- Replaced all steels and fibers and clutch plate springs, wave washer and seat washer all OEM. Each plate and fiber checked with dial calipers and placed in the exact order of the diagram. Plates soaked 24hrs prior to install. Steels installed with rounded edge towards the bike.
- Replaced slave cylinder and rod (Both OEM). greased the rod up pretty well but the seal was a little lose but I cant imagine that would be enough to cause it to do this consistently.
- Replaced all clutch fluid (Brembo) drained line completely,cleaned up the master cylinder with brake clean and compressed air/etc.
- Inspected sprocket case for cracks
- Inspected clutch cam for cracks
- Inspected inner and outer basket there were some groves (wavy type wear), I did some light sanding on the inner and outer hub to try to smooth those out a bit. I tried slipping a steel on the inner hub and holding some pressure but it didnt really bind up
- changed out 3 of the pressure plate springs with some brocks heavier springs (this seemed to help a bit) but I didnt want to go crazy and risk cracking the sprocket cover and it should work with stock springs.

I have a new inner hub coming as well as a new master cylinder (both OEM). If those dont work I'm pretty much stumped other than the outer clutch basket (they are proud of those @ $300).


What else could possibly be causing this? I'm running out of Ideas.
 

WuzzaCBXRider

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I used to add another steel to the stack on my old CB 750/852cc and didn’t need HD springs. Would that work on this?
 

TheDude27

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I'll measure it when I replace the inner basket. However I tried putting one extra "thick" steel in from my original set of steels as a test for that and it was still slipping. I put the thick one as the last steel which in hindsight I probably would have been better putting it first as to slightly "misalign" any of the grooving that may be present. Thanks for any ideas.
 

sportbikeryder

Registered
What led to this starting (when was it "not slipping") prior?

The clocking of the fiber in the offset groove is not necessary at all by the way, in fact it will cause slippage when the clutch wears. Not saying that is the issue with yours as the new clutch pack should work just fine.

I can't see how it would result in slippage, but look at the slave cylinder closely while squeezing and releasing the lever to be sure there is no movement of the slave cyl housing. Movement could indicate a cracked sprocket cover. Again, not sure how that would make it slip, but worth a look regardless.
 

TheDude27

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Replaced the inner hub and pressure plate. Still slipping.

Clutch stack height as measured: 1.970

Plates and steels:
Inner
P: .150
S: .077
P: .118
S: .077
P: .116
S: .078
P: .117
S: .089
P: .117
S: .090
P: .118
S: .077
P ..117
S: .077
P:.117
S: .077
P: .116
S: .077
P: .149
Outer

Those seem good to me.

Here are pics of everything. I did notice some black marks towards the inner part of the plates on the outer basket not sure if that means anything.

20190825_151114.jpg


20190825_150746.jpg


20190825_144023.jpg


20190825_151041.jpg
 

TheDude27

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Started after the bike sat for several years with only a few 100 miles per year since all my riding buddy's ditched me. Got some new ppl into the hobby and did a trip to mid ohio for a race late spring in the rain (I'm sure there are pics of us somewhere on the net riding through a muddy campground, since we made minor celebrity status there lol)

I thought I noticed it on the way down in the rain but chalked it up to possibly slick roads. Then we took a ride from the track Down to the triple nickel road in se ohio where I really started to notice it. I thought for sure the slave or the rod were the issue due to the muck we rode through and they were pretty nasty but I have replaced the slave and rod since with oem parts.
 

TheDude27

Donating Member
Registered
Also to add I check the springs in the outer basket for play and all of them moved but one which I understand is normal. Also the washer between the inner and outer basket measured .100in .

Really grasping at straws now, is there any way possible a rim can slip on a tire(never heard of this), I did have someone replace it prior to all this.
 

WuzzaCBXRider

Donating Member
Registered
Also to add I check the springs in the outer basket for play and all of them moved but one which I understand is normal. Also the washer between the inner and outer basket measured .100in .

Really grasping at straws now, is there any way possible a rim can slip on a tire(never heard of this), I did have someone replace it prior to all this.
Yes a wheel can spin so fast that a tire, when absolutely hooking up (sticking to the pavement) so hard that the wheel can spin. Rim locks or wheel locks (tiny bolts or screws) through the rim into the tire’s bead are typically used in extreme horsepower drag race setups. But that’s not what’s wrong with your bike.
 

TheDude27

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Your original hub / basket look great with little wear . Have you pulled the basket out at all ?
Yes I pulled the inner out and replaced it the picture is of the old inner. There is a picture of the outer.
 

TheDude27

Donating Member
Registered
Yes a wheel can spin so fast that a tire, when absolutely hooking up (sticking to the pavement) so hard that the wheel can spin. Rim locks or wheel locks (tiny bolts or screws) through the rim into the tire’s bead are typically used in extreme horsepower drag race setups. But that’s not what’s wrong with your bike.
Yea I didn't think it was the cause but I've replaced nearly everything and I'm stumped. Going to use a marker on the tire and rim and see if the orientation changes just to make sure
 



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