RZ250 Clutch slipping

[pkay]

Hiya
Finally finished my RZ250 on the weekend and got to take her for the first ride. All fun after it warmed up but when the power comes on at 6000 rpm I get monumental clutch slip. Thing just revs its head off. Has anyone else experienced this? Is it a case of needing stronger springs in the basket or new plates?
Cheers
PK

[hybrid]

Could be the oil too.
But I put half TZ springs in my LC clutch.

[JonW]

the OEM springs weaken up fast, if you reused old ones I bet they didnt measure up properly, just buy some more OEM ones and you should be golden.

you can fit better plats if you want, im told FZ750 and others will fit, but search the forums for that info.

FWIW i had boxes of old springs and clutch plates from a racer, all the spings were crap, the plates all measured fine.

[pkay]

I'll admit that when I did the clutch on this one I didn't check the springs - f*ck.......
My RGV is doing the same thing so I guess I'll get the practice on both of them.......
The oil is clean and fresh so shouldn't be the issue.

[JonW]

yeah im betting its a spring issue. you can also fit 3 HD and 3 OEM for a half improvement that wont kill your wrist, or all HD which is what i have in my 421, its fine I think, but plenty of RZ riders moan its a beast when they pull it lol.

[jools]

+1 Jon's good tip. We put replacement (Yambits) springs in our 250, but I think that they supply a heavier springs, prob to cover various bigger Yammie models. It's makes for a heavy clutch. Do Jon's thing and try fitting 3 old springs and 3 yambits springs.
What trans oil are you using? Car oils with 'friction modifiers' kill bike clutches.

[JonW]

the problem with 3 old springs is they are very weak by now, buy 3 new ones next time you order from partzilla, theyre cheap enough

[pkay]

I have a Le Mans MkIII in the shed - heavy switch gear isn't a problem - new springs on the way so I'll see how we go. Thanks Guys

[ged]

I have a Le Mans MkIII in the shed - heavy switch gear isn't a problem

Haha. I spent a year or so on a '76 Mk1 many moons ago. What a ride!

[L.B.]

What type/weight oil are you using?

[EPApolice]

Use mineral oil not synthetic, I use the cheapest Castrol stuff I can find and don't suffer clutch slip any more. You can also put another washer behind the bolt holding the spring, I don't just mineral oil.

[pkay]

Can't remember what's in the RZ gearbox but it wont be synthetic - more than likely semi-synthetic. I'm using Yamaha 2 or stroke gearbox oil or Penrite semi synthetic in the RS250, KR250, H1 and the GT380 which seems to work ok but they dont get the same power hit as the RZ/RGV.

[JonW]

if you think it might be the oil thats wrong then run some atf for a bit to clean it out. It works ok as a gear oil as well of course, but it needs changing often as its quiet detergenty (if thats a word) lol.

I will wager this is a clutch issue, and im betting on springs, but measure the plates as well... any cheapo digital caliper will suffice.

[pkay]

I checked the plates when I got the bike so they were all good as it had a stuck clutch - I'm betting on springs too. Weekend after next it's booked it.

[gman]

for what it's worth pkay. i use fzr1000 clutch friction plates in my rz350 with stock springs and yamlube 2t transmission oil. The fzr1000 plates are the same thickness but are around 2mm wider offering more surface area bite.. never had a problem and doesn't slip even after 10'000k's of abuse on a ported, piped motor. my clutch used to slip with stock rz plates.
Also i used to use motul transmision oil in some of my old (60's) 2 strokes. i had clutch slip issues which seemed to be reduced when switched to yamalube 2t transmision oil.