1980 GS850 clutch wont disengage

[Zaos]

Hey everyone!

I have a really strange problem with this bike. The clutch will only sometimes disengage, and usually works when the bike is cold the first time. The moment it gets engaged in any gear, it won't go back out of gear.

Got the bike in shambles, no wiring harness. Slowly been putting everything back together.

Replaced the oil with Rotella T6, could this be the issue? I've also adjusted the clutch cable so that it's not always engaged.

I've also heard that the clutch discs can get stuck on a bike that's been sitting a long time.

 

[Steve]

Clutch disks can get stuck. Easiest way to unstick them is to put the bike in fifth gear, pull the clutch lever and bump the starter a couple of times. It might also work if you pull the clutch lever and rock the bike forth and back a few times.

Another way they can SEEM to be stuck is if there are grooves in the clutch basket. The tabs on the clutch disks will be retained by a little friction into the grooves, and will not slide apart like they should. Put the bike on the side stand, pull the clutch cover. Remove the pressure plate and all the disks (be sure to keep them in the same order and orientation) and look for this:

If you see any of that, file or grind all of the dimples until they are smooth, clean out the metal filings and re-install the disks. Install a new cover gasket, make sure the cable is properly adjusted, you should be good t go.

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[Zaos]

Ok I'll open it up and check that out. Thanks! If i put it on the side stand I'm assuming i still have to drain the oil right?

Also bump the starter as in hit it with a mallet or try to start the bike while it's running?

 

[Steve]

No. On the side stand, no oil will escape. :encouragement:

If the bike runs (in neutral), try to start the engine with the transmission in gear and the clutch lever pulled. Using a higher gear is preferred, so start with the engine OFF, shift the transmission into fifth gear, pull the clutch lever and try to start the engine. "Bumping" in this case is merely pushing the starter button briefly, not holding it down very long, so it does not burn out the starter if the clutch is locked up.

.

 

[Zaos]

Update, removed the cover and those little dimples are there. Guess I have to file them down! Looks like it's going to be a lot of work ahead.

 

[rphillips]

Those little dimples were not a problem for me. I've never liked seeing them there, but mine never were bad enough to make the clutch not release. Are yours just little humps, or really drastic slots? I don't know how to measure what I'm trying to ask.

 

[rphillips]

What's shown in steve's pictures, should not cause the clutch to not disengage. Just my opinion.

 

[Steve]

What's shown in steve's pictures, should not cause the clutch to not disengage. Just my opinion.

The rest of the story? :-k

That bike was really hard to find neutral, but especially when cold. My theory is that the thicker (cold) oil was sticking the plates together just a bit harder. When warmed up, neutral was easier, but still not easy to find. I don't remember how long it took but it was a LONG time, I filed the notches much flatter. and gear selection was MUCH easier.

.

 

[Grimly]

The rest of the story? :-k

That bike was really hard to find neutral, but especially when cold. My theory is that the thicker (cold) oil was sticking the plates together just a bit harder. When warmed up, neutral was easier, but still not easy to find. I don't remember how long it took but it was a LONG time, I filed the notches much flatter. and gear selection was MUCH easier.


.

Same on one of mine. The gouges were worse than that though. Purely caused by destructive long-term vibration, imo.
The same vibes rattled a lot of bits on that bike to death, so much so that it became a never-ending pursuit of replacements just to keep up with it. Mind you, it was doing a thousand miles a week or more, mostly motorway miles at high speeds and 6 to 7k most of the time.

 

[Zaos]

Another update. Was kind of a pain in the ass to get the dimples out but, slow and steady.

When I removed the springs they looked like they had spray paint on them which was...strange?

Anything else I should do while this is open? Disks, plates, and springs are all well within spec so I'm leaving them in.

Mine were as bad as that pic. Just a wild guess but the guy I bought the bike from had it in pieces, engine had a cough of oil in it. Wonder if that caused premature wear?

Ordered the clutch case holder thing so I can torque down the nut holding the gasket. I'll update again once I get the bike up and going if the problem is gone!

 

[Zaos]

Looks like that wasnt the fix!

That's how it goes I guess.

Could I be using too thick of oil for the weather? It's about 20F around here on average the past few weeks. Is 5W-30 too much? On that note, any oil recommendations if not that?

 

[Cipher]

isn't t6 synth oil? If so it probably runs like water even at freezing point of water.
Are you running the engine up to operating temp and still no joy? Is this happening with the vehicle moving in each gear at a road speed within the gears range?

Or is the bike on its stand static. Even in hot summer weather my bike hates moving out of gears when not running especially the higher gears. I think that is normal.

There is a star device for the shifter and should be a protocol for adjustment should you acquire and read the fine manual.
Also do not overlook the clutch cable.

 

[Steve]

Could I be using too thick of oil for the weather? It's about 20F around here on average the past few weeks. Is 5W-30 too much? On that note, any oil recommendations if not that?

GET THAT OIL OUT NOW!!!

First of all, Suzuki recommends 10w-40 or 20w-50 in warmer weather. Yes, some of us use 5w- synthetic oil, but the second half of that is "40". 30 is too light.

Second of all, take a look at the API donut on the back of the bottle. Do you see the words "Energy Conserving" or something similar? You do NOT want that stuff in your bike with a wet clutch. I have not yet seen any 40-weight oils with the EC designation, but I would not be surprised to see some soon.

How are you determining that your clutch is not operating properly? Unless you have a spot in your state that is considerably warmer than my location, it's not warm enough to go for a test ride, so I'm guessing that you are testing in the garage, possibly on the centerstand. There WILL be some drag. Moreso with a colder engine. You should be able to apply the brake and stop the wheel without killing the engine, but there WILL be some drag that will start the wheel up again when you release the brake.

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[Zaos]

Another update, I'm blind! The oil I am using is Rotella T6 5W-40

This is a bucket bike, and somehow it's missing the rear brake master cylinder and the line. The bike is on the center stand while I'm testing all of this.

I'm still a newbie with bikes, I just figured a clutch (I drive a manual car) fully disengages the bike? Or is there enough drag while cold that you need to have the brake applied?

Thanks a lot for the help guys!

 

[Cipher]

its an oil bathed clutch and yes there is drag from the oil even when the clutch is properly adusted.
The oil should also be at running temp if your in a garage in winter michigan weather then things arent going to be nice.

Even in summer on startup the oil makes for a resounding clunk when you drop into first gear.

 

[Steve]

Good to hear that you have proper oil in there. :encouragement:

As Cipher mentions, your clutch is bathed in oil. There WILL be some drag, as the plates don't separate very far, and the oil film drags its neighbor along for the ride. As I mentioned in post #13, try slowing the rear wheel. Without a rear brake it will be a bit more difficult to do safely, but you should be able to stop it.

.

 

[rphillips]

Good luck, maybe there's not a problem. Yeah, just put your toe against the rear tire, will take a little pressure but you should be able to stop it easy enough.

 

[Zaos]

Figures I'd update what the issue was!

The clutch spring bolts were all loose, the torque wrench I had i suppose couldn't go low enough (even though the scale did).

Shifts perfect now!

 

[Gorminrider]

Yes, avail thyself of an "inch#" torque wrench. Divide "inches" by 12 to get the Ft#s. I use it more than the big one,I think. No torque wrench is intended for the lowest or highest part of their scale... most things in life are like this I believe...excepting maybe Rockets.