Preliminary data on woodruff key failures

November 25, 2003

Yamaha Motor Corporation USA

Customer Relations Department

P.O. Box 6555

Cypress, California 90630

Dear Yamaha,

On (date) I purchased in good faith a 2003, WR450F from your dealer xxxx, located in yyyyyy. Since that purchase dozens of Yamaha 2003, WR450F’s have reported failures due to a design flaw in the woodruff key starter system. The failure rate of these bikes has been calculated at over thirty percent (30%) within nine months from date of purchase.

Yamaha Engineering has recognized the engineering design flaw as evidenced by their complete redesign of the woodruff key starter system for the 2004 model. A retrofit to the 2004 design from the 2003 model is estimated to cost including labor around $700 list price.

Yamaha issued a “Technical Bulletin” number M2003-007, informing dealers to put the loctite 648 glue on the failed 2003 models crankshaft. Many who have had this fix have had repeat failures. This is unacceptable.

Please inform me when I should bring my WR450F to my dealer for them to do the woodruff key starter system upgrade to the 2004 model at Yamaha’s expense. I expect this will be handled in an expedited manner.

Thank you for your help. I will be awaiting your response.


My name

My address

cc: My dealer – his address

I got a call today from a Jim Owen of Yamaha Customer Service. He said that they have only received one letter (mine), since the TECH Bulletin was released. They consider this problem to be solved. Unless they receive dozens of letters they will not do anything further. Phone calls don't count.

Jim Owen's number is 1-800-962-7926 but you MUST WRITE a letter.

wish i knew why yamaha is being so strange about all this. i got a letter from mr.owens friday, thanking me for my letter. so i guess there were at least two letters. wonder how many they really got. you have to wonder how the big boss would react if he (they) knew how this was being handled.

I wrote a letter to the V.P. of their Motor Sports Division, Jim Gentz. A tech rep called me and wants to work on my bike. He said that they are not sure if the '04 update parts will retrofit or not, because they still don't have the parts to try it.


Interesting item in the Feb. '04 issue of Dirt Bike Magazine's article on the '04 WR450: They mentioned the problems on the '03 model with shearing the flywheel key and the '04 model has a 2mm larger diameter crankshaft/rotor.

I sent a letter and got a call from Yamaha a while later.Guess what?...They don't want to admit that there is a problem!

This will be my last Yamaha.

This is my first Yamaha and the thought of the woodruff key failing me is quite scary. HOwever, the engine on this thing is sooooo sweet that I dont think I could ever buy another bike. Ive got 1100 miles w/o a failure but Im guessing that it could happen at any time? :)

Yes, the article even mentions a recall - Yamaha Canada does not acknowledge a recall. I too have a similar story to the others - my unit #000595 left me stranded on the first ride, the starter died on the second. The flywheel came off for a second time after it had been reattached by the dealer according to the Yamaha service bulletin. I have been trying since May, to get Yamaha to take a pro-active approach, and FIX the problem. They have ignored me, and then told me "no" - the "best" that they will offer is to reattach the flywheel if it comes off again. I am in the process of emailing ALL of the Canadian dealers, and planning a consumer "awareness" campain. I would like to pool my resources with any other WR450F riders to keep the pressure on Yamaha. I will post later when I have my website up and running to illustrate what I have gone through with Yamaha. Truly shoddier treatment than I would have expected from a company that boast how it has the "best" customer service.

Keep us posted. Yamaha will try to ignore this and hope we go away....

FWIW my 03 has around 8 races on it and well over 2000 miles with no problems.


I was in the same frame of mind as you. 2600 miles and no problems. One year to the day I bought it and WHAMMO! Sheared the key. I have been looking long and hard at the 04 upgrade parts and now I'm most likely going to do that.


I would love to help you out by hosting the correspondance on my site or by providing a direct link to your site with the information.

Two (2) more failures reported this week.

<ul type="square"> Law_boy and wjc2003


This week my key failed for a second time. I had the service bulletin done on it last year prior to my first failure, then I had it done again after my first failure. Now it happened again. It looks like this my last Yamaha!!! Sorry guys But I've bled blue til I ran dry. I hope Yamaha gets a clue. Bye Bye Yam!

an excellent post. how did you collect the data? from TT?

i would like to do the same for rocker arm failure in husabergs 2002 onwards.

well i have looked threw a lot of post on this key subject looking for a problem simular to mine with the rotor bolts to clutch gear, seems like a lot of key issues but not but one with bolts issues out of a lot of pages, if anyone one knows how i can contact boozer 502 let me know i have a post in forum looking for person with simular trouble as i. and maybe we can compare notes. :thumbsup:

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