Hi, long time lurker here, hoping to the pick the collective brain trust. Bear with me ...
The clutch on my long suffering '97 m750 finally threw the towel in after 54k. Naturally, it decided to do this in downtown Indy after the MotoGP practice last year, 10 hours from home with only rocks and sticks for tools, and instead of getting a trailer or anything intelligent to get it back to the hotel (30mi away), I limped the poor bastard back without a drop of clutch fluid in its soul. Sounded like a box of hammers by the time I parked it. Luckily, the hotel was next door to a variety of hardware and general stores. So the next day, race day, woke up, did some parking lot DIY and got the clutch back ... enough to get me to the speedway for the races and back. Then I parked it til this past weekend.
These bikes: it's a wet clutch, and the slave operates from within the right side case cover acting on a pushrod in the spring retainer plate - so when you pull the clutch in, the slave piston pushes from your right ankle going towards your left. I think I would've had a better idea that the slave was going if I didn't have the stock clutch master with the coffin reservoirs. I also think the coffins aren't a good choice w/ a pair of 10º clip-ons, because angle tips the fluid away from the outlet. So my first question: the stock Brembo master is (I believe) a PS13 ... what size (or better yet, part numbers) can I safely 'upgrade' my master to, which will allow me to use a pee cup reservoir? A superbike-sized master will be overkill, I'm sure. I don't really like the pee cups, but considering the angle of the coffins ... I'm thinking it's a necessary evil. And yes, I'm planning to do the same for the front brake master as well.
Anybody have any clutch & brake M/Cs they're looking to unload? ;D
Next question, clutch basket related: I think the distinct lack of pressure in the slave allowed the important clutch bits to wobble around in there, and I can see some chunks taken out of the inside of the case cover, which appear to coincide nicely with the tabs on the clutch plates. The dings aren't huge (they're only only the beefed-up area where the mounting bolts go through the case), but I wouldn't think there'd be much chance of the basket even coming into contact w/ the case. Should I be concerned about the bearings keeping the basket straight, or is this possibly typical? Everything feels tight ... I guess I could just put it all back together and see what happens. Can't be any worse than what it's been through already. [evil]
Thanks in advance!
I'm not really familiar with that slave set-up but I don't think a lack of pressure/fluid in the slave would let any parts float around. You may want to dig a little deeper.
Quote from: Ddan on April 21, 2014, 10:34:34 AM
I'm not really familiar with that slave set-up but I don't think a lack of pressure/fluid in the slave would let any parts float around. You may want to dig a little deeper.
Yep, post some photos, something is loose.
Stay with the 13 mm. master or travel will change. You can either buy a new 13mm. with pea cup reservoir here http://www.yoyodyneti.com (http://www.yoyodyneti.com) for not too much over $100. Call and speak to Fred for proper fitment and great advice. Or you could post in "parts Wanted" on this board and hope for a good used one.
i'd find and fix the problem before you start buying shit you don't need.
without photos it's hard to tell, but i'm sure i've seen the marks the plate tangs make in small block clutch covers before. i'd probably not be overly concerned about it on its own.
the bearings in the crankcases on the input shaft behind the clutch do fail on these motors. if it is noisy, assume something is wrong. loss of pressure is irrelevant mechaincally, but it may be a symptom.