Preliminary data on woodruff key failures

Adam...did extreme do this on their own, or was it yamahas recommendation, to lap, locktite, and torque ?

tell your dealer to call tom's... they still seem to be clueless. LOL. :)

Loctite retaining compound I would bet. It used to be called cylindrical retaining compound. It is used for holding things like the taper here. I use it at work for instaling sleeves in bearing pockets or on bearings where the pocket is oversize by less than .001 inch. I was thinking of doing that. How do you get it apart? You will neet a torch and a puller. Well, I guess that is the point. ---Mike

Ahhhhhhh the hell with it. i'm just going to weld the flywheel to the crank. Bhahahahahahahahahahahahahaha.

just kidding. :)


the mechanic at Extreme is good. He wrenches for Sarah Whitmore,professional womens motocross #4. He read the unofficial TSB and said to me. "Do you want to do what this says. Or do you want it really fixed." I said "fix it like it was your bike".

So he removed the flywheel. Cleaned and inspected. Lapped the crank and rotor. Re-installed the flywheel with Red Loctite. Torqued to 47 lbs,backed off the nut and re-torqued to 47 lbs.

He said the flywheel/rotor wont go anywhere now. Like Superbike Mike said, the only way it's comming apart is with a torch. :)

Whens the last time you had to pull your flywheel??? Famous last words.LOL.

Been quiet for a while with no posts, but have been following tt daily. Since I started this chaos, by posting the first key failure, I thought I'd bring everyone up to date. I have 150 miles now on my bike since the key was fixed by my problems. I did have some jetting issues that I thought were a second sheared key, but I checked the timing by removing the spark plug and dropping a pencil down into the cylinder and rotating the engine to tdc to see if the "H" mark lined up! It would act rich at 1/8-1/4 throttle and feel like it was hitting the rev limiter early. I went from a 155 main to a 162 and solved it. Wasn't what I thought was wrong; thought it was rich not lean!! Everything else is per TT input: 48pj, #5 on stock needle, 1-3/4turns on air screw, cut throttle stop, air box baffle out, and my own full flow exhaust insert. Haven't cut gray wire yet, but get this. Was at dealer on Sat. and they let me look at the just published 2003 tech bulletin print-out for all yamaha's. Had a number of pages on the 450wr about the WR's starting system, how to cut the gray wire, removing the inserts-exhaust & airbox, cutting the throttle stop etc. Every dealer should get this book, so check it out!! Hope this helps!!


I beleive the flywheel is stock - although it came from California instead of the factory and was said to be hand machined. One thing I didn't mention, I've heard speculation from some of the Yamaha folks the taper is too short due to the space required for the additional e-start gears. Apparently the YZ 450 has a much longer taper hence no problems. I know there's been some TT discussion on this as well. Guess only time will tell. Looks like my days of riding alone are history.

Kewl, thanks for the info gloft. I pick my bike up this weekend. Hope it gets figured out so we can all feel ok riding alone.

endurodog, where you getting your bike from? just curious to see who it is and if they are making the fix on the bike ahead of time. i bought mine a couple of weeks ago and i called them last week to ask about the fix and they just played stupid? 56 miles no problems though, e-start with throttle, etc, no problems?

I'm getting it from a shop in Ely NV. Called E-Lee Yamaha. Don't know if they will do the fix or not. I figured I would ask but just plan on doing it myself. That way I know its done. $6048 out the door.

Speaking of me doing the repair. I need to get a fly wheel puller. Will just a genric one work or is there a specific one for this. Thanks in advance guys.


I understand your concern on doing it right. However, I'd caution you to consider Yamaha may not want to provide any future warranty work for the defect if they learn that the initial work wasn't done by one of their own. The guy who did my work confirmed this saying I was correct in not attempting to fix the problem myself. It may not be an issue but you never know.

Well, talked to my dealership today and here is the BS i got:

He says that Yamaha is jetting the bikes lean, which is causing the backfire which is breaking the woodruff key. He said this is unrelated to the torquing of the rotor nut. (huh?)

He said they were replacing the key. I asked if this would happen again since it's lean, and he said "Yup". He said I needed to richen the jetting which they wanted $100. He said now that I know about this problem, if the key breaks again due to the bike being too lean then they would NOT service the bike again at no charge.

What a load of bullshit!

I called Yamaha and complained, and they mentioned that their service tech should be calling the Regional Tech Advisor (RTA) for support. Once they call RTA for support, then your serial # should be in their database that a call was made.

I was told by Yamaha that jetting shouldn't matter, since your jetting will always be different for altitudes.

It really sucks being a consumer... we always seem to get f*cked!

If my bike isn't completely fixed the first time around, then i'm getting rid of it. Having to deal with crap from the dealership, and Yamaha making us waste our time researching this and making sure it gets fixed correctly is total BS!!!

He said now that I know about this problem, if the key breaks again due to the bike being too lean then they would NOT service the bike again at no charge.

I brought mine in with the baffle out, airbox cork out, gray wire cut, and jetting altered and it was fixed with no questions asked. No warnings about jetting or customer error. (You should re-jet because it runs much better that way.)

IF you have further problems, take it elsewhere, and don't give that dealer any more business. They probably didn't fix it right anyways.

For what it's worth, I use the electric start:

* Frequently.

* To start a cold engine.

* To start a hot engine.

* With the throttle open.

* With the throttle closed.

* On sunny days.

* On cloudy days.

* For the joy of hearing it work.

* To make my riding buddies jealous.

* etc...

And it's given me NO PROBLEMS and NO SHEARED KEYS since I let a competent dealer fix it.

Socals I would agree.....your biggest problem is a very poor dealer. Get rid of him.

Just a FYI there was no backfire when my bike sheared the key.Hang in there it is worth it. :)

If this is Yamaha's fix, we are in deep trouble. I have never seen a manufacturer handle a serious problem so poorly. By the way, if there is any question as to failures in California......

"mandatory Modification WR450F"

serial numbers affected: CJ04W-0000037 to CJ04W-0003669

model types: 5TJ2 and 5TJ4

needed parts:

90280-03001-00 woodruff key

5TJ-15451-00-00 gasket

needed tools:

90890-04141-00 flywhell puller

reason: the woodruff key may break (no reason given

only a pic of a single key with an odd stripe,

probably wear, on the brink of dying?)


- disassemble and remove stock key

- reassemble with new key according to the following:

- put Loctite 648 on key and whole crank taper

- place rotor onto crank

- torque rotor nut to 40 Nm (29ftlbs)

- wait 2 minutes

- remove nut

- put Loctite (no specific number given) onto nut and washer

- torque to 65 Nm (47 ftlbs?)

- reinstall engine side case (my assumption: here you

should use the gasket, advisory doesn't say so explicitly)

- and refrain from starting engine for 24h! (very odd)

end of procedure


Is this something issued to CA dealers? I have a WR450 bought in CA. Should I call them?


That was actually from a different thread and from Europe (I think) The CS person I talked to at Yamaha checked with the regional tech in the shop and that seems to be consistent. Although I still would like to get the actual TSB (if anyone has it please post) content and number.


Perhaps Yamaha has not updated it's dealer web site to show another Technical Bulletin, but according to this same site, I see the Bulletin as M2003-005 and do not find one under number M2003-007. As of today, we have not been sent or faxed any bulletin from Yamaha Motor US regarding any update to M2003-005.

Looking at Bulletin # M2003-005, it has the corrections that allow the dealer to "paste" the correct procedure in it's manual. Cutting through all the words, Bulletin # M2003-005 simply shows that one needs to remove the nut, put it back on and torque to 47 ft. lbs., remove, and repeat the 47 ft. lbs. torque. I do not see anything that indicates lapping the crank/flywheel or using any Loctite compounds except for the small bolts that attach the starter clutch. I’m not saying these additional steps are not warranted; these steps are not in said bulletin.

Please disregard my previous post.

As of today, we just received Technical Bulletin # M2003-007. The essence of the bulletin is what has been posted before. As dealers, we are to modify all unsold units. Also, contact your Yamaha dealer and make an appointment to have them perform a "90 Code Warranty Request" from the Technical Bulletin cited above, that will be free of charge.

I cannot post the actual bulletin, as I have no way to scan for a PDF file.

Bought SN 2240 on Thursday (3/27), had mod done on Friday at San Diego area dealer and rode 40 miles today in Socal desert. Great bike and no problems so far.

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