2011 XC250 clutch issues

[Hamburgler]

Hey all,been having the same issues for a while but this past weekend,while racing it got considerably worse.Below are the symptoms and below that is what ive done so far.

Symptoms:

Issue started out as a dramatic increase in vibrations to the handle bars while riding for more than a couple of hourse and especially when riding with the throttle pinned on long straights or roads.At the end of the day it was super bad,bike was always just screaming while not producing a huge amount of power for the amount of revs.

Have had issues with clutch slipping but bled it super well one week ago and that seemed to solve the issue.I was once again able to actually start in gear,although i was still getting the bad vibes.

This past weekend,i raced a very gnarly enduro and in the tougher sections the clutch got real bad,most easily identified symptom was that the clutch wasnt able to be feathered any more.It was either engaged or not at all.And it would only engage in the last half inch of lever release.Riding like that was tough.

I could also swear that while in the worse sections,while feathering the clutch i could hear a terrible rattling from the engine.

Bike had great power throughout the race,no issues there.

What ive done to fix it:

tried different oils,from 15-40 Amsoil dirtbike oil to 15-50(recommended for KTM) then back to Motul oil and back to MOTOREX(currently in the bike is amsoil dirtbike oil 15-40)
Ive bled the clutch to the degree that i would say was well bled.
Fully drained the system and blew air thru it all and re-bled.

Note:There are a few things i think it could be.I havent changed the damping elements.And also(this is the likely culprit),the black rubber cover on the slave cylinder piston is "chipped",its missing a small piece of rubber on the side.ill take a pic today or tomorrow.

Thanks for any help

 

[Aube]

What's the condition of the discs, plates, basket and inner hub? Are they within spec? You haven't mentioned the condition of the clutch discs, these wear especially with racing. I would start with the main components that are known to wear, notches in the basket/center hub can also cause issues by preventing the discs from coming back together properly.

Slipping isn't usually a symptom of a bad slave unless the pressure won't release when you let go of the lever. Air in the system would generally prevent you from disengaging the clutch. When you go to bleed it is there still pressure without having depressed the clutch lever?

Marty

 

[Hamburgler]

Your right,my bad.A couple weeks back i actually swapped my clutch pack for a brand new one and it still have the same issues.As for the the other hardware,clutch basket etc,its all good as far as i can see.BUT i havent checked the damping elements yet.

When you go to bleed it is there still pressure without having depressed the clutch lever?

Is there still pressure where?

 

[KevinAnderson]

Are there notches in the clutch hub of basket?

 

[Aube]

Pressure In the line/slave? I don't know if it's common on motorcycles but on cars/trucks lines can occasionally collapse on the inside holding pressure. If that was the case it would keep the clutch slightly depressed.

These might seem like stupid questions..but..

You swapped all the plates?
You have the right amount in the right order?
When you say they look good you mean 0 visible wear/no notching?
Clutch springs are all good? all there...
You don't have a rekluse with an adjustable slave right?

 

[zedro]

My money is a bad clutch bleed, you're describing all the symptoms of a clutch pumping up with heat, so it is pushing on the clutch a bit (slipping it) but also being mushy because of the air. Hotter it gets, worse it gets. No different than a brake except the engine heat alone could pump it up.

Edit: a bad master/slave seal could be affecting the bleed.

 

[Aube]

My money is a bad clutch bleed, you're describing all the symptoms of a clutch pumping up with heat, so it is pushing on the clutch a bit (slipping it) but also being mushy because of the air. Hotter it gets, worse it gets. No different than a brake except the engine heat alone could pump it up.

Edit: a bad master/slave seal could be affecting the bleed.

Good point, you would also have some amount of fluid loss. Could be difficult to notice as it wouldn't take much. That would only do it when really warm though, is that the case? No slipping when cold?

 

[pat74]

You should talk to your sponsored dealer. Woody for me has been providing incredible support, he has the expertise to trouble shoot problem quickly

 

[zedro]

Huh no kidding...I would accept fender stickers in exchange for a professional engine tuning :mrgreen: