Hello Mike,

Had the same slipping clutch on a warm 450 single.
Sent the friction plates to BCA Friction Material P/L
They replaced the friction material with Kevlar.
No more slipping clutch, no more dragging cold clutch.
Best few hundred dollars I’ve spent on a clutch

Graeme

Mike, what I’ve done on the fleet in the past. Beadblast the steel plates and I fitted 3 out of 6 clutch springs with Suzuki GSX1100 clutch springs. Or do all 6 if your Steve Austin. Boucher.

Thanks for the suggestions both gents.

I have added another driven steel plate and changed to a heavier wet-clutch oil. And have learned (or read) to soak the new fiber plates in oil before installing. If this does not help then I will swap to some very-strong Barnett springs (they come with the old F1 Kevlar kit they used to sell, and are not needed to work on the dry clutch), and try the beading.

Looking around on the internet for info it is amazing how this has been a problem for about four decades now —-even the very modern small wet-clutch engines still do this. The disc sets are NOS Surflex, and I wonder if there is now better material from some another maker, like Newfren or Adige.

Darmah Dave races, and wins with in AHRMA, a dry-clutch 650 (750cc) Alazurra, and that engine does not have this problem. Maybe that is the ultimate solution.

Other than that, this little bike is really a joy to ride.

Mike

Added the 2.70mm springs, another steel plate, and went to 20-50 oil --- and no slip. But the pull was tough and tiring on the left hand and wrist. I am surprised that this newly-changed dogleg lever, that I added after the track day, really helps so much. Not as plush as the long one on the Pantah race replica, but easy to live with. Went ahead and changed the brake lever to the same, just for symmetry. Who would have thought?

Strange how most Jap bikes never had this problem. Throttle springs as well.

Made a few revisions for this year. Engine is now 705cc (88x58mm), using 696 pistons, Carrillo rods, Jprecision heads, two horizontal 900SS ie cams, a dry clutch transmission, aluminum clutch hub and basket, aluminum flywheel, lightened straight-cut primary gears, and very early versions of Malossi 41mm carbs. I like this modern aluminum clutch side cover; it is easy to add lines to and from an oil cooler, just need to block the internal oil feed to redirect it there. And, went to Bridgestone radials; the 130/70-16 radial front on a 3.5 rim is actually narrower than the Avon 120/80-16 bias-ply on a 3.25 rim. But the 160/60-18 rear on the 4-inch rim is wider, and since it has a much smaller diameter than the previous bias-ply tire I used a rear sprocket with one less tooth than before. MikeV

Hey Mike, I went back on this build a bit. This could be one of your best! great job! Lou

Like a fine wine…. Better with age!
Well done Mike

Thanks guys. I was hoping to get some of you out after ground hog day. Good to see some are still alive.

I really like the look with Campys more, but i have had those tires sitting on those Marvic rims “a while”. Time to use them up. I think the narrower front will help with turning some, it certainly makes fitting inside the fender easier! One benefit of thinner radial sidewalls.

Oh, i also removed the funky power-on and starter buttons that concerned Carlo so much. Now has a normal switch on the left clip-on inside the clutch master cylinder/lever.

MikeV

I know I'm very stressed, but in this group it's the only time I can talk