clutch got me stumped

[6pak]

:sign67:I've gotten some pretty good advice so far, so lets try again. '89vr. new clutch (yamaha oem). Changed fluid and bled-no air. New oil(when clutch was changed. After the bike warms up, the clutch STILL slips when I get on the throttle. I am fresh out of ideas. By the way, I cleaned out the little hole in the clutch resevoir. I feel like I'm bangin' my head against a wall on this.

[sarges46]

You're not by any chance using "energy conserving" oil are you? Cant use that stuff as it causes clutches to slip.

[6pak]

Using spectra 10-40 motorcycle lube- been using it in my wing for 10 yrs, but then again the wing doesnt have a hydraulic clutch

[6pak]

by the way, what is energy conserving oil?

[muffinman]

You may have a weak spring or more than likely you need to take the hard plates back out and put a non directional finish on them.

I use a DA sander with 220 grit paper to do this but Gerald and Dan did it by hand and I believe it worked good for them.

Jeff

[GeorgeS]

you changed the plates, did you put in New Springs ??

[sarges46]

by the way, what is energy conserving oil?

 

Its used mostly in cages. It is slicker....therefore more conserving I guess. Plays havock on bike wet clutches.

[6pak]

are you saying to just rough them up like with an orbital or a mouse sander? Not for sure what a non directional finish is. My guess is to just scar them up a bit?

You may have a weak spring or more than likely you need to take the hard plates back out and put a non directional finish on them.

I use a DA sander with 220 grit paper to do this but Gerald and Dan did it by hand and I believe it worked good for them.

 

Jeff

[hipshot]

are you saying to just rough them up like with an orbital or a mouse sander? Not for sure what a non directional finish is. My guess is to just scar them up a bit?

 

i think the most common terminology, is "cross hatch".

this means to sand in one direction only, then sand the opposite direction only.this method gives you 13.7 million little "x"s, to insure a good scuffed surface!

lol

hopes that explanation helped.

just jt

[okscooter]

Do you have access or know anyone who has a glassbead blaster. This works really well for deglazing the steel plates.

Your profile says you have an 89VR, a single diaphram spring. Buy a heavy duty spring from John at PCW Racing, follow his instructions, it won't slip anymore. My 88 VR would lift the front wheel off the ground when I speedshifted to 2nd. Took a few Harley guy by surprise one day leaving a stoplight.

[Yammer Dan]

The circle on the back of the oil bottle should not have any lettering in the bottom half of the circle. It should be empty. If there is lettering there it is telling you it has friction modifiers in the oil.

[GeorgeS]

Have you pulled out the Clutch Slave Cylinder ??

 

If your 87 is over 50K and this item has never been changed or rebuilt, this might be the problem.

[Condor]

The clutch only slipping when it's warm still raises the question about the expansion relief hole. IF the clutch hooks up cold, and then starts to slip when the engine gets hot, it's gotta be a plugged hole. Are you sure it hasn't plugged up again?? If there are crystals in the line there's a good chance that it might have. Take the cover off the reserve and semi-slowly squeeze the lever. If the hole is clear you will see a small imperfection on the fluid surface as the fluid briefly squirts out of the hole. Not 100% on this but oil with friction modifiers should cause the clutch to slip even when cold....

[Yammer Dan]

Not sure on that one Jack may have something there I would check holes good first.

[6pak]

Checked both holes in master cylinder-open. Roughed up metal discs with 220 grit sandpaper. Have a new slave cylinder on order from local dealer($67.82). It's gotta come from Atlanta, expected friday. That may give me enough time to get the old one out. Will keep ya'll posted.

[Gearhead]

Energy conserving oil is marked as such on the container and contains "friction modifiers" (such as moly, maybe??) to reduce friction for better mpg, at least in theory. It was mandated by the EPA or somebody on lower viscosity oils (which also improve MPG a bit). 10W30 is the highest vis oil that is energy conserving. 10W40, 20W50, 15W40, mono grades - none of them are energy conserving.

 

It doesn't matter if you have a hydraulic clutch or not for friction modifiers to affect it, what matters is that you have a wet clutch (in the engine oil), and all Jap bikes that I know of have this.

 

Jeremy

[Condor]

Checked both holes in master cylinder-open. Roughed up metal discs with 220 grit sandpaper. Have a new slave cylinder on order from local dealer($67.82). It's gotta come from Atlanta, expected friday. That may give me enough time to get the old one out. Will keep ya'll posted.

 

What's got me stumped is that the clutch starts slipping when the engine warms up. Perhaps the slave is corroded enough that it isn't allowing the pressure plate to apply full pressure to the plate pack. Enough to hook up when the oil is cold, but not enough to keep things from slipping once the oil heats up??? Keep us posted, this is interesting.....

[Rocket]

:sign67:I've gotten some pretty good advice so far, so lets try again. '89vr. new clutch (yamaha oem). Changed fluid and bled-no air. New oil(when clutch was changed. After the bike warms up, the clutch STILL slips when I get on the throttle. I am fresh out of ideas. By the way, I cleaned out the little hole in the clutch resevoir. I feel like I'm bangin' my head against a wall on this.

 

Is there enough expansion room in the clutch master cylinder, for heated fluid? If it is too full, the clutch may not fully release, possibly cause slipping.

 

Also, there is a replacement Barnett pressure plate available, for the 1300 version of the 1st gens. This is similar to the one on the 1200 model.

[Gearhead]

"What's got me stumped is that the clutch starts slipping when the engine warms up. "

When the engine warms up, the oil properties are different. Also, he's probably not honkin' on it as much when cold.

Jeremy

[mbrood]

I chased something similar for a while... solid clutch when cold... a couple miles down the road and fourth and fifth would break loose under heavy load (grabbin' throttle!).

 

I went through darned near everything and by then everything was CLEAN.

 

Then I noticed that the clutch lever had no real "free play" when it was hot...

 

I could bleed the clutch and have just that little (1/8th") lever free play but after a couple miles nada.

 

I pulled the hose off the slave and tried to feed fluid UP the line... no go.

 

On MY bike, when the lever was relaxed to it's stops, the piston was STILL not coming back enough to OPEN that little relief hole in the reservoir! I filed off a TAD of the short piston push rod that the lever pushes... assembled the lever and blew into the master outlet (Well, yes, it WAS on the bench and without fluid...) I had to file just a tad more and then when the lever was remounted and relaxed... voila!

 

Did a reassembly and couldn't get rid of the air for nothin'. Finally broke the master reservoir bajo bolt and bled THAT spot and THEN a regular bleed went fine... and after a few miles... still a nice firm clutch grab and STILL had that nice 1/8th" free play at the lever.

 

Your mileage may vary but that's what it was on MY bike.

[Condor]

 

On MY bike, when the lever was relaxed to it's stops, the piston was STILL not coming back enough to OPEN that little relief hole in the reservoir! I filed off a TAD of the short piston push rod that the lever pushes... assembled the lever and blew into the master outlet (Well, yes, it WAS on the bench and without fluid...) I had to file just a tad more and then when the lever was remounted and relaxed... voila!

 

Did a reassembly and couldn't get rid of the air for nothin'. Finally broke the master reservoir bajo bolt and bled THAT spot and THEN a regular bleed went fine... and after a few miles... still a nice firm clutch grab and STILL had that nice 1/8th" free play at the lever.

 

Your mileage may vary but that's what it was on MY bike.

 

 

Yeah, now I recall that. Good one Mike...

[6pak]

If the new slave dont work, I'll try that b4 an aftermarket pressure plate or spring. Now you've got me thinkin' about the free play being next to zero when the bike warms up. It'll have to wait for the new slave though, as I pulled the old one last night, and I'm not installing that agrevatin' thing but one time. I'll let y'all know. 6pak.

[mbrood]

NOW is a GREAT time to check for that "freeplay"... if you blow UP the hose going to the master, you SHOULD be able to blow up the line, into the master cylinder and THROUGH that tiny hole... if you can't... pull the lever... this lets the piston FULLY retract. Now if you can blow through... you've solved ANOTHER problem all at once... you need that piston free enough to open the relief hole WITH the lever mounted. I only had to file a bit off the flat end of the push rod that the lever pushes against the piston.

[6pak]

The slave won't be in till friday, so I'll try that tomorrow.Since today is the 4th, and I'm staying off the roads today, I'm just gonna enjoy a beer or 12, and run the grill. Besides, I've still got the wing, although I try not to ride it too often. Tn. law says that with the antique tag I'm not supposed to ride it except to shows, parades or organized events. It's usual use is on patriot guard missions. I'll keep ya posted. 6pak.