Slipping clutch

[duaneage]

Oil can contaminate a clutch, no doubt. But look for the sudden easy stuff first. I don't think the clutch springs are bad. I did my 650 clutch last month and the springs were perfectly in spec after 27 years. They measured 38 mm and the service limit is 36.4

I replaced them anyway because I had a new set in hand. I donated them to another forum member visiting my house so should he need springs he has them but it's unlikely that is the problem. Oil contamination would be the third thing to check, right after the cable ends and then measuring the plates
Spec on the fiber plates are 3.0 mm new, down to 2.7 mm each, or if any single plate comes up real short like 2.5. The total thickness is important so if you loose .3 mm per plate and one happens to be .5 under then the rest will suffer.

I installed a barnet kevlar clutch for 112.00 delivered. I'm real happy with it so far.

[salty_monk]

I use Castrol GTX 10w 40 with no problems. There are no friction modifiers in it.

Dan

[chef1366]

I use Castrol GTX 10w 40 with no problems. There are no friction modifiers in it.

Dan

SSSSHHHHHHHHHHHH=;\\/

[JTsGS650]

The solution...

Well thank you all for your responses. All very good advice. However, I'm embarrassed to say that I went home last night and checked the clutch cable and both the piviot arm side and the lever side were in need of adjustment .

The clutch engages in the middle of the lever travel now and no more slipping. For some reason I keep getting lucky with this bike. However, now I wonder if the cable suddenly needing adjustment is a sign of it starting to go...

[physics-teacher]

Clutch adventures

I know you've got her fixed now, but here's a tip for you if you ever do go in there again. Make sure you have the proper side gasket in hand before you split your cases to get at the clutch. I ordered one in advance off ebay, then opened the cases to replace my springs. The old gasket had been on there 26 years and it came off with great difficulty and in many pieces. Soon the ebay clutch side gasket arrived and it was the wrong size. Now the bike sits for another 10 days while I order from a competent dealer. My clutch was slipping with proper adjustment and when I replaced the springs it worked perfectly. Spent a lot more for the gasket than for the springs! Also, I noticed the Suz springs I got from the dealer were noticeably thicker than the OEMs in my 81 650G. And the pull at the lever was a little harder, but not obnoxiously so. Looks like there was a factory upgrade or uprate some time during the last quarter century (ha, ha!)