GS650GL '81 clutch slips @ high load/high RPMs

[BP_redbear]

Sometimes when rolling into the throttle in different gears (2, 3, 4, or 5), and above 5000rpm, the clutch seems to slip (when at near-full-throttle). The rpms rev up very rapidly, faster than I am accellerating. At this point, I roll back off the throttle a bit.

Is it a safe bet to install new clutch springs?

I have owned this bike for 5 or 6 years.
I am unaware of any previous work being done on the clutch.
The oil has been changed very recently (Pennzoil 10W40).

Oh, yeah... the clutch lever has plenty of free play, I do not believe that it is dragging. What I have noticed is that if I reach down, I can rotate the clutch release lever on top of the gear case (clockwise when viewing from top) a few degrees.

Shouldn't the springs rotate this arm to full-retract (clutch fully engaged) position when the hand lever is released?

[tkent02]

All these old bikes need new springs, they've been compressed thirty years, don't spring back as much as they were designed to. Springs will probably fix it.
You may need some plates too, but usually not, it's easy enough to go back in with new plates later if you need to.
Your shop manual will have all the specs to measure everything.

[Dogma]

If the mechanism is like my 850, the springs do release the clutch to fully retracted, but the release mechanism has more travel than the clutch itself. So, so free play at either lever is normal.

Even in the unlikely even that tkent02 is wrong, new OEM springs are cheap. Order a set with a gasket and see where it gets you. For me, I also had to sand all the plates with 220 to get 28 years of shiny glaze off.

[BP_redbear]

Thanks.
Springs it will be.
And a new cover gasket (too bad, I just installed a new gasket on the clutch cover because the old one was leaking).

BP

[bonanzadave]

Sometimes when rolling into the throttle in different gears (2, 3, 4, or 5), and above 5000rpm, the clutch seems to slip (when at near-full-throttle). The rpms rev up very rapidly, faster than I am accellerating. At this point, I roll back off the throttle a bit.

Mine did that and I ended up smokin off one of the fiber plates and scuffing a metal plate.

http://www.thegsresources.com/_forum/showthread.php?t=125593&highlight=clutch+slip

[duaneage]

I pulled my 30 year old springs and they were within specs, both height and pressure, but they are cheap so I replaced them anyway. I used a barnett clutch in mine and it performs very well. I would not go with tougher springs, just stay away from oil marked "energy conserving" as they seem to ruin the fibers.

[physics-teacher]

My 650 was slipping pretty badly when I got it with 26000 miles on it. I replaced the springs and this fixed it for about another 20000 miles, when it started slipping when cold. I replaced the friction plates and now it runs perfectly, hot or cold. I could tell the clutch had never been worked on before I got it because the gasket was a total nightmare to remove in tiny pieces. When I went in there the second time, the new gasket I installed at 30000 or so just lifted out beautifully in one piece and now I'm reusing it.

[BP_redbear]

Same with my old gasket. Unfortunately, I used spray Permatex gasket sealer on both sides of the new one...

I am definitely going to install new springs.

Just in case, what is a ballpark figure for a set of new plates?

TY.
BP

[czav]

If you have free play at the lever on the the case, the springs are a good first bet. Too many many revs of slip on those plates and it will get even more pricey.

[duaneage]

Barnett kevlar clutch ran me 115 dollars, OEM is about 6 dollars a fiber, 2.00 a spring, figure 65 dollars that route but your dealer price may vary. The kevlar is supposed to be better, I have a few grand on it and no problems so far.

I bought 1/32 inch thick gasket paper and cut my own gasket, took 10 minutes. I even cut one for another GSer, used a scissor to cut it out and a paper hole punch to make the holes.

6 dollars for a roll of gasket paper and you can do 3 gaskets easy.

[BP_redbear]

If plate replacement proves necessary, is it necessary to replace ALL plates, drive and driven?

I have a genuine Suzuki shop manual (and a Clymer book), plus micrometers, dial indicator gauges, dial calipers. I will certainly check the plates for spec and glazing while I am in there changing out the springs.

When the release lever on top of the cover is not all the way retracted, I can feel a vibration in it with my finger, and when I manually move it all the way retracted (CW) the vibe stops (with free play in the handlever still).

This is why I questioned that if the springs were supposed to move this lever all the way out normally. We'll start with new springs...

[Dogma]

Thanks.
Springs it will be.
And a new cover gasket (too bad, I just installed a new gasket on the clutch cover because the old one was leaking).

BP

If it was recent enough, you may be able to keep the previous gasket. Keep the new as a spare, I guess. When you put it back together, make sure to smear grease on the both sides of the gasket so it won't stick in the distant future.

I don't know what the deal is on mine, but I've been into it a couple times this year on the same gasket with no leaks. This is the gasket that was on the bike when I got it 3 years ago after sitting in a garage for 14 years. Maybe I got lucky. But I still have a new spare ready.

[Steve]

If plate replacement proves necessary, is it necessary to replace ALL plates, drive and driven?
..

Not sure which are the 'drive' and which are the 'driven', but all you would need would be the fiber plates. (I believe they are the 'drive' plates.)

While you have the cover off (whether doing just the springs or if you get into plate replacement), clean up the metal plates by scuffing them up with some 220 sandpaper.
That will assure good contact with clean metal.

.

[gadang]

I have the same issue with my 650G. I even used the same oil that you have but when I took it in for a valve adjustment I had them change the oil again with a MS grade oil instead of automotive. I believe the Pennzoil was "energy conserving" and it started slipping after I changed it. It is better with the new oil but it will slip if I am giving it a little "love" and it bounces over a bump in the road...then it will slip.
I have some new springs, fibers and a gasket sitting on the bench...just looking for the time.

By the way....I freaking love my GS!!!!

Sappy huh?

[82Shafty]

Pay attention and write this down, which way your steels come out of the clutch basket; there is a flat cut side and a rounded side!