Opened up '00 YZ426 Clutch - Im completely dumb-founded - HELP!!!

Hey Guys!

Please help me! I am completely confused! :)

Tonight I opened up my 2000 YZ426 Clutch Housing and pulled the clutch apart. The whole process took approximately 30 minutes. Far easier than I expected. :D

What I found was completely beyond understanding.

I removed the spring screws off the pressure plate and looked at the springs. Nothing out of the ordinary. No damage, no apparent cracks, nothing. Then I removed the pressure plate. No apparent damage either. Nothing

Then I began to work on the nut holding the inner hub to the shaft. The nut was hardly on. It took only about 2 turns and the big nut was off! All lock washers, etc. were in their proper place.

I pulled the inner hub and clutch packs out. I inspected the inner hub, nothing really noticeable. I did feel on the edges of the teeth, slight grooving where the clutch/friction pack made contact. I also saw the oiling holes...nothing seemed out of the ordinary - No ????

Then I checked the basket. The clutch basket appears to be the correct version. The fingers on the basket had the raised side on the inner portion, so if you look at it from the outside it looks like the letter U. NO real scaring marks on the inner fingers. Just a little roughness on the surface.

I flipped the basket over and looked at the springs. Nothing really noticeable. Gear teeth were okay!

Then I inspected the clutch/friction pads.The fiber sections look pretty warn, with some scoring. The metal plates closest to the hub looked fine and smooth. The farther out towards the pressure plate you went, the more scoring and burn marks appeared. All on both sides.

My friend and I inspected all the gears behind the basket in the engine block and found some scaring on the gears teeth. Sorta like meshing wounds. We also found a few bits of metal filings.

The oil in the bottom of the pan was a brownish/gray. I always change the oil after ever ride. The bike has been sitting for a while. I ran my finger on the bottom of the crankcase pan, and felt a little bit of what I could only describe as silt like material.

I am completely confused! :D

Please help? What have I missed. I checked the push rod. It was okay. I checked the cross rod through the block to where it connects to the throwout bearing/plate. Okay

What gives?

Why is my clutch chattering?

Why am I having such shifting problems?

Why is the bike so grabby?

Could it just be my clutch cable being stretched? Could that be why it never keeps adjustment?

Please, I don't know what to do!

I ordered the upgrade parts for the '01 that will correct the grabbiness, and Im going to order new clutch friction/fiber plates, and springs...But now what do I do about the basket?

I feel that the Hinson Basket could only help not hinder, but what about the pressure plate and hub?

I'm gonna feel like a jack-ass if its just the clutch cable!

Please be merciful, and offer up some wisdom!

Any positive ideas or suggestions would and are appreciated!



YZ426 Confused

Was the center hub nut loose? If it was, the whole clutch assembly can move and the rod NEEDS the clutch hub to be held tight to work. If it loosens too much the result is play at the lever and no disengagement.

Originally posted by James Dean:

Was the center hub nut loose? If it was, the whole clutch assembly can move and the rod NEEDS the clutch hub to be held tight to work. If it loosens too much the result is play at the lever and no disengagement.

Hey James,

Yes, the nut was loose. She was only on about 2 turns. The nut came right off! I didn't understand it because the geared washer was in place, and the locking washer was also in place. Everything seemed normal except that one nut.

How could that be loose? It makes no sense-

Now what?



Randy - you need to sit back, drink a beer, and take a nice deep breath.

Before this turns into another 30 postings of clutch opinions and gudges against Yamaha, let's talk this over.

First, that lose nut may have caused some concerns with the clutch wearing quickly and not performing up to well as the metal filings. And just general abuse can do this too.

The film on the cases sounds fairly normal on this matter so just wipe it up. And remember, not everything comes out of an engine when you drain the oil. Okay?

Then, clean all the other stuff up really well and put the thing back together. Then go ride it before you speculate on anything else or purchase any new parts.

Most likely, the thing is going to perform just as well as it did the day you got it.

By the way, you're not using Pennzoil are you?


Randy, Both James and DaveJ give good advice. I definitely agree with DaveJ and say just put it back together, make sure it's all to specs and ride it. You can still put the update parts in it when you get them. The little bit of marring to the gear and the metal you found in the bottom is most likely due to the excess play from the loose nut. I guess this all demonstrates a very common problem MOST of us fall victim to when it comes to wrenching. We ALL fail to keep it simple at times. We get caught up in what we read of other's problems and reach a conclusion before really looking into the cause of something out of the ordinary. The best advice any of us should have given you is to have first opened it up and physically look at it. Keep us posted on how it goes.


like a kid again!

00 YZ426F

01 TT-R125L (my son's)

91 CR125

83 YZ490

74 Hodaka Super Combat(gone but not forgotten!)

Hey Guys!

Thanks for your input.

Let me first say that my mouth is silent here concerning Yamaha, because of what was apparently not found. I will, step by step, try and figure this out.

Should the issue be just the loose nut, a stretched clutch cable, and the upgrade parts, I will, as a Man of God, humbly post a full apology for speaking out against Yamaha concerning MY clutch woes.

Believe me, opening that housing and finding very little was indeed humbling, confusing, and at the same time, gratifying! I wanted to find a problem as so to resolve it-not to stike out with. Finding only a little wear and tear and a loose key component is in itself very humbling.

I agree with your statement to put it back together and see what's up. I don't know what riding with no problems are like, since I've had the clutch issue since Day-1. Yesterday was the first time that housing had ever been opened!

My intentions are this:

1. Replace the clutch friction/fiber plates and springs. ( small investiment )

HEY, WHOSE PLATES/FIBERS & SPRINGS DO YOU USE? Stock or after-market. If after-market, whose then?

2. Add the new '01 replacement parts.

3. Change out the clutch cable. ( new one wouldn't hurt )

4. Im still undecided as to just go ahead and

purchase the HINSON basket. A pressure plate and inner hub just don't seem warranted here-not yet anyway.

Then I will ride!

If I still have an issue, then I will still search.


I lean not on any excuse. I am totally accountable for the words I have posted in THUMPERTALK.

I have spoken truthfully about how Yamaha and my dealership has treated me. Regarding other riders issues, I admit, I may have let my youth, and inexperience talk before the wisdom and integrity of my faith.

Again, its humbling. I will make restitution if warranted!

As far as the oil situation goes. I have been using 10W-40 made by Spectra-Lube. This is what my dealership recommended.

I have thought about using synthetic oil. It works so much better in my vehicles. However, I do realize that a vehicle is quite different from a Dirtbike!

I checked the forum and saw the postings regarding Mobil 1 Synthetic 15W-50. I wasn't overly thrilled with the replies. Equal amounts of positives and negatives.

I think I will try EXP from Bel-Ray, or maybe Yama-lube. If y'all come to me with the same, I'll follow you're advice.

Guys, believe me-if its just that nut and a clutch cable, I'm gonna feel like a jack-ass!

What do y'all think?

God Bless!


YZ426 Kicks - Chillin' OUT!

[This message has been edited by YZ426 Kicks (edited 04-11-2001).]


I think you got great advice about your clutch. James is right on the money about the nut.

I just wanted to add that I have been using the 15-50 Mobil 1 for over two month now and have had zero problems. My clutch has worked perfect.

Good Luck



01 YZ426F #85 Vet C

Randy, In regard to your oil question. I don't want to start another lengthy opinionated debate again, but go back and find my post titled "motor oil". Read the article I referenced and then read all the replys. Take everyones opinions for what they are and base your decision on the imperical data presented by the article and the "experience" good or bad voiced in the replies. Just as forloop stated he's used mobil 1 with good results. As for your clutch, most "opinions" that I've heard/read are that the stock friction plates are fine.

I can't really respond though on what's a better investment money wise. The Hinson basket is a very good investment if you don't mind spending the money. It's very good insurance and goes a long way toward rider confidence. It also really makes your clutch operate better IMHO. It's machined billet aluminum vice cast and spins truer and IS much more durable. Hope this helps!


like a kid again!

00 YZ426F

01 TT-R125L (my son's)

91 CR125

83 YZ490

74 Hodaka Super Combat(gone but not forgotten!)

Go with the White Bros. clutch plates. I've talked to many people that "use" them and they say they're by far the best.


If you do decide to go with a full synthetic like Mobil 1 15w50, now would be a good time, with the new clutch plates. It's not good to run petroleum based oils until your clutch plates get worn and then switch to synthetic. There may be some glazing on the plates and it won't react well with the synthetic oil. But if you put in new plates by all means go with the new oil. I've been using Mobil 1 15w50 for almost a year and half. I checked my CB drive gear a couple weeks ago and while I was at it pulled the clutch, which is all stock. Everything looked almost new. Just my experiences.

" I did feel on the edges of the teeth, slight grooving where the clutch/friction pack made contact. Just a little roughness on the surface."

Don't put it together until you make these smooth!!! Use fine sandpaper or something else. Also , I recommend a basket & it doesn't have to be a Hinson. I have a Performance Engineering Basket & it was only $139 (helped a lot). Other than that my clutch is stock & is cured (no "01 parts)

[This message has been edited by Clod Thrower (edited 04-11-2001).]

Grooving on the clutch basket will cause the clutch to get grabby. Clod made a good point, file or sand the grooves smooth. The plates will catch or shift inwards as you release the clutch lever and then suddenly grab with these grooved notches. This is pretty common after a season or two of hard riding with an open class bike. When it gets really bad the bike will feel like you dropped the clutch out hard no matter how smooth you try to be. It can be worse with a cold engine also.


[This message has been edited by James Dean (edited 04-11-2001).]

JBM: Was it you who advised to pull the clutch lever in for about 30 seconds while waiting for the engine to warm up? Whoever gave that advice is owed my gratitude. Ever since I've been doing this, my clutch is buttery smooth when I engage it for the first time of the day. Obviously, by doing this, the clutch plates get oiled very well before that first engagement and that grabbiness is avoided.

Randy- give it the gas and hang on... and smile... the rest don't matter.

Hey Guys!

Thanks for all the info! I really appreciate it!

It appears that I am going to have to pay for all this myself.

I've been talking with Yamaha today, and despite my talking pictures, sharing honest evaluations of the situation, sharing your thoughts, and stating the facts about my dealership-it appears Yamaha is ready to leave me high and dry.



Despite my telling Yamaha that the two calls they claim to have made to the dealership have been answered by blank stares by the dealers mechanical dept.

Despite my telling Yamaha that I have been continually bringing this issue to the repair centers attention.

Despite my telling Yamaha that the dealership refused to open the clutch in front of me and allow me to inspect the parts.

Despite my acknowledging that the basket is not the apparent clupret, just the center nut that was almost off.

Despite a witness, with 17 years of dirtbike experience, who photoed the complete disassembly.

Despite being humble and forward, honest and no where near demanding.

Yamaha apparently is refusing to do anything to help. No help towards the clutch pack that was scored and burnt, or even the upgrade parts because I OPENED THE BIKE.


Now with all fairness, I couldn't stay on the phone with Yamaha because I was at work. So, I have to call them back tomorrow ( 4/12 ). But still, they are now disavowing any responsibility.


I'm gonna try and see if they'll at least cut a good break on the clutch pack and the upgrade parts. Frankly, I can't justify anything else really.

I'm gonna cough up the $$$ for the Hinson Basket, but what about the inner hub? There is some grooving on the teeth. Mind you it isn't gouged, or deep. It feels like little waves.

So I ask-What do you do about the hub?

I'll get the new plates & fibers.

I'll get the '01 upgrade parts.

I'll get a new clutch cable.

How would you approach Yamaha?

Thanks Again!

God Bless!


YZ426 Kicks - Chillin' Out

I found that the nut for hub/basket on my '00 426 was loose also, despite the lock washer being in place and tabbed over. Others have found the same thing, so maybe it's not worth loosing sleep over.

I'm not sure about the the reinforcing ridges on the tangs proving that this is a "good" basket. This idea may have come from a poorly written and misleading article in a magazine. Could someone who has had a cracking and/or failed basket, post a pic or tell us if their basket looked unusual in any way? (aside from the damage)

'01 426 owners seem to have no complaints about their clutch, so maybe it's best to use Yamaha parts (even though some aftermarket parts may be better). Last time I checked, the friction and steel plate part no.s for the '00 and '01 were the same, except for the last friction plate and the two parts that go with it.

I found the inner hub to be quite deeply notched after relatively little riding time. If I were to replace or file the hub every time it notched, I'd need a new one every two weeks. This is not in my budget, so it stays.

I've messed with my clutch a lot (Hinson basket, grinding push rods and then putting new ones back in). Recently, it started working reasonably well, but why - I don't know.


Holeshot's Page

[This message has been edited by holeshot (edited 04-11-2001).]

Randy, Most of the stuff you described is NORMAL wear on clutch components. The fact that the retaining nut was loose excelerated wear also. I don't want to start a lengthy debate here, but since you stated you had the noise and clutch engagement problems from almost day one and continued to ride the bike without investigating you just compounded the problem. I don't really know what issue you have with Yamaha, again other than an unscrupulous dealer. If you choose to replace the inner hub, I would definitely go with the Hinson or maybe Performance Engineering piece since these will provide more durability. You could file the ridges down as suggested but this is just a temporary fix and may cause your clutch to still be a little notchy. Any material taken off just increases clearance between the parts and the excess play again excelerates wear. So, your new fibers, etc. would wear faster than with a new inner hub.

When you put your clutch back together, use some blue loctite on the nut. Clean the threads real good with a good degreaser and then some acetone (that's what loctite uses for a primer). I'm sure my reply will instigate many more opinions, but this is what I recommend. Good luck. I hope you get it running soon and enjoy the bike!


like a kid again!

00 YZ426F

01 TT-R125L (my son's)

91 CR125

83 YZ490

74 Hodaka Super Combat(gone but not forgotten!)


Yes it was me that suggested pulling in the clutch during warm-up, thanks. It works well for me as well. That is the key, warm up good, and get oil back to the plates. This seems to help with that.

Originally posted by holeshot:

I found the inner hub to be quite deeply notched after relatively little riding time. If I were to replace or file the hub every time it notched, I'd need a new one every two weeks. This is not in my budget, so it stays.

Every 2 weeks! Get real ,I did mine once & it will be good all summer. Much better than putting a notched one back in.

Clod Thrower:

So you filed all of the notches out of the inner hub? You're a lot more ambitious than most people I know. The sharp steel plates hit against the aluminum inner hub, so they notch very quickly.

I could see filing the notches out of the clutch basket (many people do). Since the softer and considerably less sharp fiber plates hit the basket tangs, I can ride for years without notching it. There were no notches in my basket, but I made a clock out of it anyway.

Stinkin' fast riders like you probably notch the basket in a matter of months, because you're throwing Great Clods of Dirt and, of course, there's hardly anyone on the Planet that can keep up with you. :)


Holeshot's Page

[This message has been edited by holeshot (edited 04-12-2001).]

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