Yamaha woodruff key Service Bulletin, finally!


I hope you have better luck with #418. I have #413, of course, it's still clean since it failed in the parking lot. The rotor nut was checked, the carb jetted richer before starting it. Then they even lapped it before it was ridden all to no avail, the key sheared with less than a mile on it. Yamaha is replacing the crank and rotor, the crank is in, the rotor well, 67 on back order, 38 in transit who knows when we'll see one, glad we didn't sell the KTM.

Oh contraire,

I have in my grubby little hands a Yamaha TSB numbered m2003-005 titled "Owner's /Service Manual correction - revision of rotor nut tightening torque" dated 3/7/2003.

I you have an e-mail I would be glad to attach a scanned copy of the first page.

Why not just scan it and post it here for all to see? That should resolve the rumor mill issues...

Bonzai :)

Ahh, must be they have done this for the folks who didn't have this insert in their manual. If this is the case, as i'm sure it is, the much expected TSB that actually fixes the problem that is causing all this mayhem is yet to be released.



edit: would love to see it just the same. Email me at sabooo@ptd.net

Have just learned that there may be a svc bulletin number m2003-007 which will be of great interest to this forum if it contains what its rumoured to contain.



Saboo, Do you have a spy at Yamaha :):D :D Or maybe you bugged their phones :D

I don't have a new 450 but I have been following this woodruff key issue a bit here, figured I'd throw this in the ring...

Chaindrive has it pretty close really, if the taper is not self seizing, its not machined right or there is a material issue. Personally, I've never seen a proper taper not seize, it just doesn't make sense.

But what he said about the height of the key interested me. If true, the key could prevent the taper from ever closing... that would explain why loctite would help this problem. Not a real fix, but enough to help keep the flywheel from vibrating itself loose, killing the key.

Anyways, you don't want it any shorter than absolutely necessary though. While it is to prevent shear, it's not to carry the load. This is obvious to those of you shearing keys.. if it could handle the load alone, it would not have sheared.

Thus, you can try this... mount the flywheel with no key, no loctite, nothing... torque it to spec as if you were doing it for real. Take a sharpie and mark the nut and shaft with as clear a line or mark as you can... then repeat using the key in this time, and see if the nut bottoms to the same spot.

If the nut is not the same both times, chaindrive may have figured it out.

hope that helps y'all

haha, none of these, but I've been on the phones all day and rattling as many cages as i could get ahold of the bars on. Have not gotten sufficent confirmation of this latest TSB, but am sincerely hoping its the one that will correct the actual problem instead of band-aid'ing it.



let us KNOW. I am going to hold off doing anything but checking the torque until I find out "The rest of the story" :)

sorry, but loctiteing the flywheel to the crank sounds like a bandaid to me.

my dealers service manager talked to a yamaha rep. today.

the rep. told him.. THERE IS NO PROBLEM.

ya ok.. whatever. :D:)

I agree. There are two probable causes that i've seen so far - a machining error in either of the two bits involved in the taper mating, or a flywheel key that is incorrectly sized for the application. Loctite doesn't change either of those situations, only glosses over them to delay failure.

In the meanwhile I've taken my bike to a very reputable shop that specializes in machine work and off-road racing vehicles (bikes, quads, sleds, etc) to have it opened up and looked at. In the event that the taper is a lousy fit, they are going to have a go at determining just why that's so, fix the problem, and give it back to me. Yup, i'm paying for this out of my own pocket, but at least i'll get an honest answer.

Bike may or may not be done tomorrow, so not sure when i'll have anything to report, but I'll start a new thread either way. If there is a problem, hopefully i'll be able to give a bit more insight into it, and on the chance that my bike comes back free of defect, perhaps it will allow some WR450 owners to breath a little easier when they're out on the trail.



I would, but you can not attach a file on this DL.

I am going to work with the TT people and they said they may be able to post it for me. I sounds like this is not the TSB we want anyway; it is actually m2003-007 that we need to see. I was told by Yamaha CS that this TSB was globally faxed to ALL dealers yesterday and they should have it. I called mine and he said he did but ABSOLUTELY refused to fax it to me stating us internet hotheads would start trouble if they didn't keep these things to themselves. I told him trouble is already started!!!!

Well to settle the issue once and for all. I have in my hands, hot off the press service bulletin # M2003-007 dated 03/26/03 "DAMAGED GENERATOR ROTOR(FLYWHEEL) WOODRUFF KEY. The fix is what most have thought, "lapping the rotor" and use of "Loctite 648", not the loctite others have spoken about (see Loctite website). The Bulletin is 5 pages and is for ALL 2003 WR450 bikes, the dealer will repair free of charge, "in warranty or out" (stated in bulletin) You can tell if yours has been repaired by looking at the serial number on the steering neck. If a punch dimple has been made yours has already been repaired (BY THE DEALER OBVIOUSLY). If not, take it to the dealer for them to fix free of charge. This looks like a good repair ( I guess Yamaha did some homework) The Loctite 648 is very strong and has great properties (check there website) If any body wants a copy a this bulletin PM me and I'll be happy to send you a COPY to your e-mail address. Hope this ends all the controversy and problems for all who own this bike. This is truly a great ridin' bike and I love it. Would'nt trade it for any KTM.


us internet hotheads would start trouble if they didn't keep these things to themselves.

I think we wish they actually had kept the trouble to themselves and away from everyone's expensive new bikes. As it turns out (so far), we were ahead of them yet again. Tell that guy I said he was a pompous ass and an idiot. We are trying to fix THEIR trouble, which is more than he can claim.

If a dealer is intentionally "keeping known problems and/or their solutions to himself", that constitutes fraud in my book. He should not be trusted or franchised to sell a tricycle.

You don't actually intend to ever spend a dime at his place again, do you? Right this minute some poor sucker is about to unload 15 to 20% of his annual take-home pay into that jerk's business for his dream machine... :) Does he sell used cars on the side? Or hold a political office? If not, he missed his calling.

Did you explain to him that first and foremost you are his CUSTOMER, not some "internet hothead" and he owes you the truth? He wants to see internet hothead, pm me his email! His attitude is worse than the problem.

Whoa Chaindrive,

I was kind of paraphrasing/adlibbing on the "internet hothead" thing in my attempt to be humorous. My dealer did give me verbal information about the TSB. The issues is in FAXing over TSBs. Extreme no no in Yamaha/Dealer policy and would not do it.

MxnDoc, I agree the Yamaha is a much better bike than the KTM. As far as the correct TSB m2003-007, could you e-mail it to me? sdhoward@yahoo.com thanks.

"Extreme no no in Yamaha/Dealer policy"

WHY??? I think their policy needs to be fixed...

A little off topic. Not to bash KTM, I do like there bikes. My buddy had a 2002 250 ext (2stroke). It had a problem where the ring would hang up in a sub port. He called KTM, they said in had been a problem on that model. Then said they would not fix it! This was a design flaw! Eric Gore said he got them all the time it was fairly common. The powervalve cover also cracked. They said too bad you have to but a new cylinder to get one! It does look like it was cast as part of the cylinder so we will let them slide there. No bike is perfect. Even less companys are perfect. The bike companys are not to bad compared to other industries. ---Mike

I just contacted my dealership about the TSB (M2003-007). They didn't know anything about it. They said they will call me back. When they called me back, they said my bike wasn't in the range of SN's and not to worry about it. I told them that it was my understanding that ALL WR450's were covered in the TSB. He said he would call me back. When he called me back, he said that all WR450's are included, and they all should get the repair. He told me to bring the bike in and they would do the repair and order the neccessary parts. He said if I brought the Bike in on monday, I should have it back by friday, as long as the parts are not on back order. This does not sound too unreasonable. I understand that sometimes these things happen, and the manufacturer usually does their best to clear them up. I've had several Yamaha's, I'm not brand loyal to any one brand. I've had bikes with problems before that were taken care of promptly, and some that weren't. The things that are really starting to rub me the wrong way are A. Gluing the flywheel/nut, And most disturbing, B. the fact that if it weren't for stumbling accross TT and the info provided by it's very astute( :))members, I probably would not have Known about this untill my bike broke in the middle of nowhere and (god forbid) I paid for the repairs myself. Just when does Yamaha plan to notify their costomers??? :D Do they plan to notify them at all? How many people have paid for the repairs not knowing about the TSB, and will never be reimbersed? Sorry to be so negative, but my local Yamaha dealership has gotten somewhere between 20 and 30 grand from me in the last few years. I know that may be small peanuts to them, but, you anger enough people and it starts to become a problem.

I thought the dealerships were supposed to contact the owners.I had my bike fixed under warranty before the TSB.They lapped the crank and rotor and didn't locktight them.That was 500 miles ago.I think Yamaha is just trying to find a way to make sure it doesn't happen again.

I would also ask your dealer to order the parts and then set up a time to bring it in.That way if the parts don't make it your not out riding on the weekend. :)

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