Possible explanation/fix for the some of YZ426 clutch problems.

[RichardM]

I put up a web page with my experience of the YZ 426 clutch problem. I hope you find the information of use. I will be on vacation at the San Raphael Swell until Tuesday and will check back to see what others have to say about this information then. The pics take a little time to load. Enjoy! http://www.motox.org/yz426  

Richard<p align=right>04-13-2000 :Edited

 

[Tex426]

Thanks for the information Richard. I have not experienced the problems thus far on my less that 20hours 426. Do you have a number for Yamaha support to get more information about how to grind the end of the pushrod? You may have found the source of the problem and not just fixed the symptom.

 

[CHIP]

Very informative info Richard. I have been having a little trouble with my clutch. I was hoping that a good mechanic could help me alleviate some of my misery. It does not in any way form or fasion have a smooth release. I have adjusted it over and over. I am actually going to talk to MXTuner this weekend in person to try and see if I am doing something wrong and to see if he can show me the error of my ways. Maybe there is a connection with the problems you are having. The action the rest of the time is fine(ie: when the bike is in motion). I tried to find a number for Yamaha other than there hotline to order brochures and could not, I caught wind of a possible recall on the clutch assembly from a DRN post. My shop said that there wasn't recall but that I would probably know before they would.

------------------
Chip
__________________________________________________                                              
If It's Too Loud, You're Too Old!!!
__________________________________________________
00 YZ426F (mine, all mine!!)
00 XR70R (my son's)

<p align=right>04-13-2000 :Edited

 

[RichardM]

Got back from the Swell. Grinding it down did not fix the problem. But one thing I did not try was switching to Yamaha R 4stroke oil .I will let you know if there is any more info.<p align=right>04-18-2000 :Edited

 

[Thumper448]

Richard,

&nbsp;&nbsp;&nbsp;&nbsp; I would be very interested in what happens from here on out with your pushrod problem.&nbsp;&nbsp;I experienced the same growling/dry plates symptoms.&nbsp;&nbsp;In the beginning my clutch would even screech when coming out of a tight corner with a short approach to a jump.&nbsp;&nbsp;I disassembled my clutch and found that my friction plates were essentially dry and my metal plates were brown (burnt).&nbsp;&nbsp;Also, I found metal shavings and scoring on the big end of the pushrod.&nbsp;&nbsp;I took your post and my parts to my dealer last night and they are going to contact Yamaha on Monday, 4/24/00.&nbsp;&nbsp;I have also asked them to look into the problem with the pin in the linkage that is mentioned in other posts on this site.&nbsp;&nbsp;Any further info would be appreciated and I will share anything that I find out as well.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Stacey A. Weston
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; District 14&15 30+A Motocross

 

[RichardM]

I am taking the bike in on Tuesday. They will take another look at it. I will let you know of any new details. The oil change to Yam-R did not seem to help and shaving the part down did not seem to make a change either.

 

[RichardM]

I want to reflect on my 426 problem. It does seem to me that the clutch is defiantly not getting enough oil. After looking at Hinsons literature, one of the features the mention is better oil flow. This could be the reason why the Hinson clutch basket resolves the problem on my friends bike. I am going to try to get Yamaha to fix this problem first, I am finding more people are having this problem locally. I have been asking around to see if others with 426 have this problem. Some are already out of warr so they just accept it. I am finding that more vets and older guys who are not as hard on the clutch buy these things and not as many of the young clutch abusers. This is only an observation but may explain why some don't report it or don't ride the bike long enough during the warr period to figure it out. I may have to buy a new clutch basket but that would put a big negative mark on Yamaha reliability in my book they should buy it. I will just have to see if they take care of the problem. I am curious as to why everyone does not see the problem. Some people on the DRN said they have not seen it and it makes me wonder what is different about their bikes. I bought some Mobil1 to test but have not put it in yet. Another person on DRN states it causes the clutch to slip on a 400. I would welcome more lubrication I would think in my situation so I may try this if Yamaha has no fix.

 

[J.B.426]

I have experienced this clutch problem as well. I took the whole clutch apart and found that everthing looked new, except for very minor scratches on the cover side of the pressure plate. I couldn't find any corresponding scratches on the clutch cover either. At the time I took it apart, I had been running Yamalube 4. Since then I have switched to Mobil 1 15w50 and I have not noticed a difference, for better or worse, with the clutch. I do know that if I warm the bike up real well, I get very little if any chattering. I haven't had much, if any, of the grabbiness that I've heard other people have. My bike is long out of warranty, I got it in December, and since the clutch looked pretty much new when I pulled it out, I have been trying to warm it up good and trying not to worry about it. It's funny, I didn't start hearing the chattering sound until the bike was about 2 months old. I'll just take it day by day. Tuner had posted a while back that he heard that Yamaha was recalling the clutch, but I haven't heard anything else about it. Please keep us informed of your findings.

 

[penguin]

Anybody remember the 98 YZ400 kickstart levers breaking on the early production bike? because a relief hole was drilled to deep, weakening the part?&nbsp;&nbsp;Sometimes production tolerances on the assembly line can get pretty out of spec before somebody figures out what is happening.&nbsp;&nbsp;It could be one of Yamahas parts suppliers is providing poorly machined or out of spec components and the guys on the assembly line don't know any better and just slap the bike together, and then out in the real world, you and I find out the hard way and then Yamaha catches hell.&nbsp;&nbsp;It has happened before and it will happen again.&nbsp;&nbsp;Thank God for forums like this, that can get the word out , and save someone from a bad experience with an otherwise fine machine.

 

[Todd737]

&nbsp;&nbsp; I too am having clutch problems.
&nbsp;&nbsp; Some of my symptoms were: engine knocking, clutch grabbing and slipping.
I took it to Houston Yamaha and they said the clutch housing was broken. They are getting in touch with Yamaha to see if there is a recall. They have heard of MANY problems with the 426 clutch. I have a couple friends who are experiencing the same symptoms.
&nbsp;&nbsp; I will let you all know what I find out as soon as I hear from them.
If anyone hears anything definitve, could you please e-mail me.
&nbsp;&nbsp;

 

[CHIP]

&nbsp;&nbsp;Today I road for the first time with the Mobil 1. It made a world of difference in my clutch. It wasn't near as grabby as it had been. After it had warmed up it acted like a totally different clutch. I also noticed less noise than before. I still need to fine tune the clutch lever adjuster but thankfully Yamaha put the quick adjust on the YZ426. It makes it a whole lot easier.

------------------
Chip
__________________________________________________                                              
If It's Too Loud, You're Too Old!!!
__________________________________________________
00 YZ426F (mine, all mine!!)
00 XR70R (my son's)

 

[RichardM]

Update:

The "possible fix" did not work as I posted before. I changed the oil to Yamalube R which seemed to help but did not resolve the problem satisfactorily. My bike was quickly running out of Warr. The next step was to grind the shaft down some more and deepen the spiral grooves which they did but since Ron at Rocky Mountain Cycle (the mechanic in the picture)  had already taken the clutch apart I had him put in the Hinson clutch basket. I rode my bike for a couple hours at the track tonight with no sign of the problem. If someone out there has the problem and does not want to put in a clutch basket like I did then I would say you should grind on the shaft. Worse case you have to buy a new one. Hinson basket is $250 or less with mail order. I would also tell anyone who has this problem to run Yamalube R through a couple oil changes. If it doesn't help try mobile 1. It may help or hinder the problem, I don't know. Since I have had problems I am going to be a sucker and only use Yamalube R. With my discount it is within a dollar of Mobile one. I did talk to a guy at the track today that did not have the problem on his 426. He has only used Yamalube R. My conclusion. His push rod was closer to tolerance thus the clutch got more oil. Yamalube R does fix the problem and I just didn't run it long enough. It could be a weight thing. I am almost 100 lbs heavier than the other guy. The president of our MX association is as thin as a rake and has the problem as well on his 426 but weight would seem to only exacerbate the problem. Hope this helps others out there but it seems for those having the problem the Hinson basket is the only way to go. Pretty crappy on Yamahas part, they got to know this is a problem. Maybe someone will start collecting serial numbers and hand them to a lawyer to start a class action law suit. As much as I hate lawyers and law suits some times it is the only way to make a manufacture live up to a Warr. I hope Honda produces a 4 stroke. If it proves to be solid I will have my name on the waiting list (for the second year model only)Update:

<p align=right>04-28-2000 :Edited

 

[Tony Williams]

A local San Diego guy's new 426 has the infamous clutch problem. He claims that he has a Hinson clutch basket on order, and that there is a multi-week back order.

I was in North County Yamaha today, and they have the Hinson basket in stock. :

760-432-9501

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Tony Williams, San Diego, YZ400F

 

[MX Tuner]

This is weird. I've never experienced this "problem" on any 426 I've ever ridden. I understand your frustration with your problem but you seem to think this is something that affects all the 426s. And then you start making class action law suit noises......whatever.

------------------
MX Tuner
[email protected]

 

[holeshot]

&nbsp;&nbsp;I find this situation weird also, because I haven't had this problem on my 426, and I've abused the clutch as if were a two stroke. The dealer I bought it from says they've has no such problems on any of the many 426's they've sold. After trying different oils, I've settled on Castrol Syntec (synthetic blend), which I can buy at the local auto parts store for 2.50 a quart. However, thinking that the problem is related to oil choice is just grasping at straws. Yamaha goofed somewhere, so some of the 426 clutches have problems and some don't. I'm sure Yamaha knows what the problem is, but won't admit to it because they would have angry customers demanding a free fix.
&nbsp;&nbsp;Although my clutch works smoothly, I don't expect to get more than a year out of the plates (the clutch on my CR250 went 2 1/2 years).

 

[RichardM]

Mx Tuner

I know too many people locally who have the problem to say it is a minor isolated incident. There have even been people on the net with this problem. In fact one of them posted that he was going to have you look at it personally that was CHIP I believe.

You stated "but you seem to think this is something that affects all the 426s. "&nbsp;&nbsp;Please do not put words in my mouth as you have done in the past. Reread every post nowhere did I say every YZ had the problem. In fact I stated "I did talk to a guy at the track today that did not have the problem "&nbsp;&nbsp;So how you come up with the idea that I think everyone has the problem is beyond me. As I said at the beginning of the post, this is my experience. Look and see above how many people do have the problem. Just because I don't have the pin linkage transmission problem does not mean that there are bikes out there out of tolerance for that problem.

You do not understand my frustration or the others on this site that are experiencing it because you never have. Did you look at Chips bike and feel it? A class action law suit is not for those like you that do not have the problem but for us who do and run out of warranty or have to replace a brand new part under warranty because the manufacture won't admit to it. I have no plans of doing it but if some one with some balls gets a lawyer involved I will gladly add my name to the list.

Byron Wo** MX track owner had the problem and blew the basket.
Tim Ph**** MX track owner also had the problem.
David Cla***** President MX organization has the problem.
Myself.
Another friend was recommended by a dealer to change out the clutch basket after he broke it in, he is a police officer. (He did not want to take the chance)
I did not include their names because I don't want to make them public but I will email you their email addresses personally if you do not believe me.

How about on line:
Chip
Thumper 448
JB 426
Todd 737
Tony Williams

You try to put words in my mouth. You then play down the possibility that this may be a wide spread problem by sayin "all" the 426s youve ridden have never had the problem and dismiss that Yamaha may have a responsibility to fix this problem.......whatever.

 

[CHIP]

RichardM,
&nbsp;&nbsp;Tuner and I were never able to connect up. We may still in the future but I have not arranged anything. I will say, if anyone doesn't believe there is a problem then they should ride my bike. It is driving me crazy. i just got my dealer to locate a number for me to call. This dealer here is sort of a pain to deal with. The salesman that I have been talking to have become friends he has been a major help. He cares a lot more than the owners do. I pulled the cover(as you can tell, my post was a little premature about the Mobil one, the problem is still there when the bike is cool) after pulling the cover I noticed that the basket looks as if it passed QC without being deburred. It looks as if the plates are catching on the splines where the burrs are. This may have caused uneven wear, I dunno just a guess. Nonetheless, there is a definite prob with the clutches. I will be following up with many many phonecalls to Yamaha. I am a very easy rider. I have only been on the bike about 9 or 10 rides. I find all of this to be ridiculous. There is no reason for them not to have a recall on the clutches.

------------------
Chip
__________________________________________________                                              
If It's Too Loud, You're Too Old!!!
__________________________________________________
00 YZ426F (mine, all mine!!)
00 XR70R (my son's)

 

[YZWrench]

I have also had the grabby clutch problem, so I tore down the clutch on my 426 Monday and found the fiber plates pretty dry but the basket was ok except for the sharp edges on the fingers (sharp edges = cracks). I deburred the basket, soaked the fiber plates in oil for 1 hr, and modified the pushrod for more oil flow. The clutch worked great running up & down the street but that was after being assembled dripping with oil, I'll give it the real test this weekend. Say, why was my YZFWrench username deleted?

Phil
'00 YZ426

 

[Airastro]

I have a new 426.&nbsp;&nbsp;I have had it for about a month and have approx 8 rides on it.&nbsp;&nbsp;So far I have not had a problem ( knock on wood).&nbsp;&nbsp;I use Yamalube 4r.&nbsp;&nbsp;My question is this- How long did it take for people to start noticing clutch problems?&nbsp;&nbsp;Is this a problem that seems to rear it's ugly head with no regards to amount of use, ie. from first ride to several hours of use on the bike.

 

[RichardM]

I noticed the problem after about 4 rides.

I have another interesting theory as to the clutch problem from another mechanic from a different shop. I will post it here when I am a little less sleepy.

 

[Todd737]

Gentlemen,
&nbsp;&nbsp;&nbsp;&nbsp; A quick update on my progress.
I have yet to pick up my bike. (slow arriving parts.) However, they tell me that Yamaha is aware of the problem and that I am getting a redesigned clutch basket. They also tell me that Yamaha will cover the cost of this repair.
&nbsp;&nbsp;&nbsp;&nbsp; It should be ready sometime next week. I will get back on here as soon as I pick up my scooter and let you all know what ACTUALLY transpired.
&nbsp;&nbsp;&nbsp;&nbsp; My fingers are crossed. he he
&nbsp;&nbsp;&nbsp;&nbsp;

 

[YZWrench]

After a 3 hour ride yesterday I found my clutch worked perfectly, no more grabby/chatter BS. Also, I'm using Mobil 1 oil.

Phil
'00 YZ426

 

[samson]

I am also having a grabby clutch. Really sucks for starts.&nbsp;&nbsp;I got my bike before Christmas and didn't notice until after new years. (late Jan or Fe

&nbsp;&nbsp;I was at Montclair and they had a 426 in that ws complaining about clutch and they couldn't figure it out. Since then alot has come out about the clutches and my extended warranty may not cover this. I hope Yamaha can help otherwise it's Hinson for me.

Big Fred, Ragdoll Racing, Phoenix, AZ

 

[JB]

i've had my 426 2 months. still haven't figured out how to ride it, but no clutch problems. using castrol gtx 10/40. iv'e abused it like a two stroke, and lugged down low. knock on wood

 

[CHIP]

I am finally able to write about my clutch. I took it to me slightly inept Yamaha dealer. They agreed that there is a problem with my clutch and reported back to Yamaha corp. about it after they did a quick fix WITHOUT asking me. They took the metal plates and turned them around and reinstalled them in my bike. I was a bit leary of this but they tried to assure me that it will fix the problem of the grabby clutch. I have to admit after the bike is warmed (about 5 minutes) the clutch works the way it did new. That is the problem though. When new it worked fine too. I still believe it is the basket and I will recontact yamaha on it Monday to ask if they agree with the quick fix and will they still honor this if the problem comes up again. has anyone heard of this as a fix before and do you think it sounds right. To me, it sounds a bit suspiscious.

------------------
Chip
__________________________________________________                                              
If It's Too Loud, You're Too Old!!!
__________________________________________________
00 YZ426F (mine, all mine!!)
00 XR70R (my son's)