YZ CLUTCH issues

Okay, My 03 YZ 450 is having clutch issues....:excuseme: so I just replaced the Friction plates, Springs, and robbed some new Steel plates from a WR426 clutch set, and put them into my Hinson clutch Boss, Basket, and pressure plate. The clutch deosnt seem to be slipping but it will engage itself and stall even with the lever pulled all the way in.

I should point out i did wear a bit of a groove into my clutch boss cuz i ran a WR 426 clutch in there by accident for about 3 rides. The groove is barely there, and my machinist and the head tech at the dealership i work at said it will be fine, just run it.

What do you think is going on here?? The parts manager thinks its a warped steel plate- but they are brand new!! help please!!!

> Where is the groove? On the outside diameter of the boss?

> What brand are the plates?

> How long has the clutch been in place?

yes, the bit of groove is on the outside diameter of the boss. were the clutch engages onto it...

the friction plates are genuine yamaha, the steels are white bros.

ive had the clutch in there for maybe an hour

Give it a little more time to "burn in".

do you think thats the problem or is there a possibility of something else?????? either way way ill let her burn in a bit more...

Prolly a stupid statement but you have it adjusted properly?

I'm guessing so, becuase you seem competent with the machine but I was just thinking it could be something overlooked maybe?

... it will engage itself and stall even with the lever pulled all the way in.
I think it hinges on what exactly you're saying here. If the clutch simply does not release as it should, or begins to drag more and more as it heats up to the point where it won't release, it's probably just new.

If, OTOH, it releases well, but then suddenly engages without warning, I would think there was a problem there. Something loose, perhaps.

I just put a complete '06 Hinson clutch setup into my 07 (to utilize having an extra plate) and at first the clutch wouldn't disengage AT ALL...I had to start the bike in neutral, give it a push and run along side it, then hop on and pop it into gear...It's gotten better after a few hours ride time, but the bike is still pulling with the clutch lever all the way in, although will not stall out when stopping, but I have to keep the brakes depressed or find neutral qiuckly to keep from rolling...Only thing I did differently than the install instructions called for, was I meant to soak the friction plates in oil only overnight before the install, but I didn't install it until two weeks later (family priorities) so the friction plates soaked in oil for two weeks...I can't imagine that having anything to do with it since they're partially in oil all the time in the bike anyway, right?...

I'll add too, that while riding, it seems to work killer, and the "grippy" engagement point of the clutch is right where it should be, it's just the bike won't fully stop pulling even with the clutch all the way in...But that seems to slowly be improving...Also, no amount of adjustments help, and the clutch lever feel/action/freeplay feels dead on, and I highly doubt my cable is stretched (bike only has about 15hrs on it)...


One of the things regarding adding an extra plate to the '07 is that the '07 has a longer release arm to reduce lever effort. This also reduces pressure plate lift, which is why the 9th plate was removed. Each pair of plates must be given a certain amount of clearance in order to release, and that clearance times the number of plates determines the required lift. Your drag issue with the extra plate should clear up if you use an '06 release arm.

You da man, grey...Seriously, you got a paypal account? I'd like to buy you dinner...I knew it had to be something like that...I thought maybe the push rod (#19) was a hair too short due to the extra thickness (I haven't checked yet to see if the push rod is same part # from 06 to 07)...So you're saying replace the push lever (#20) with the 06 one because of being shorter it requires less travel to fully engage, correct?


...So you're saying replace the push lever (#20) with the 06 one because of being shorter it requires less travel to fully engage, correct?


Fully disengage, yes. Save your money until after it works.

Right, right, disengage...I just checked, the push rods are the same from '06 to '07 also...I'll order the different push lever today, and try that out, and let you know...

Do you think I should bother with a new cable as well?...I can't imagine it'd be very stretched with such few hours on it, but the clutch components were pretty worn (basket/plates)...Possible?:lame:

If the cable can be adjusted correctly, the length is good. If it also operates smoothly, there should be no problem with using it. Unless it was externally damaged, or packed with dirt, it should really be fine.

Just a quick update...Changing the push lever worked like magic...I'm so happy with the way the clutch works now...I've never riden a bike with the clutch so "dialed in" before...Really happy with putting the 06 Hinson set on my 07...Thanks so much for the advice, GR...Who know's how long or how many people I would've had to go through to figure out the lever needed to be switched (they even look exactly the same)...Not too many people even understand why I switched it to the 06...

something else you might want to check. i had a similar problem with a yz426. i had a lot of play in the arm before i felt any resistance at all. checked where the plunger pushes against the pressure plate and had 1/4" of travel before it even touched the pressure plate. i added 3 small washers behind the ball to take up the slack and got full arm travel.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now