Preliminary data on woodruff key failures

I called my dealer in regards to the bulletin you posted and asked him about it. I referred to the numbers you posted also. He said he looked and the only thing he has on his computer (via internet) is about the new torque value. Got anything I can tell him to get him going in the right direction? He sells a lot of bikes and has quite a few wrenches working in there so I think we must just be looking in the wrong place.


I too didn't find the Service Bulletin on the Yamaha web site for the dealers. That is why I had to correct my previous post, as I received it in the mail on Saturday. Ask the dealer you are working with to call their RTA and have them fax a copy to them.

Dealer called me back about 10 minutes after I posted. Said he just got it in the mail. Will do fix as soon as I drop bike off. Thanks for the ACURATE information!

I just shooting the breeze with my dealer here in Australia... as a point of interest, I asked and he said they have a service bulletin for the flywheel nut... didn't go into details, but the word is out there now, so no dealer should be ignorant of this matter...

Phantom Duck, if you can e-mail me the PDF, I will host and post it here...



the service manager at my dealer just got the tsb as we were talking on the phone goes in tomorrow.

hopefully this whole problem will soon be history. :)

Hey Poway Rider! How was riding with ThumpDaddy650? I'm so glad to hear that your dealer was savy to the problem and already did the mod for you. Me and ThumpDaddy (& Rich too) will be keeping an eye out for you Brother! Thump On and welcome to the Family! :) It doesn't matter what color your bike is, just as long as you gas it! We are gonna have FUN! :D

Hey Rokatt88, sorry to break ranks and go with a blue bike! As Rich will tell you, I was really torn between one of the Hondas (450 or 650), a KTM 525 or the WR450. I found out about the potential Woodruff key issue before I made my purchase and was willing to take the risk. I called Yamaha directly, talked to four San Diego area dealers and decided to buy it anyhow. I was pleased with the ride and felt like it rode and handled somewhere in between the Honda CRF450 and the XR650. ThumpDaddy650 did have to rescue me on one very steep climb. He's a great guy. I hope to see you and the Posse out there some time soon! Regards, Poway Rider

Hey PR, Don't be sorry for breaking ranks! We need variety in our hood, Dawg! :) When it's time to replace Der Pig, I'm gonna get the best bike for me that I can. I've been following the WR450 forum to keep up with the latest steed. The XR is a great bike for what T-Diddy & I do. Rich loves his CRF450. A year from now the choices are gonna be sweet! :D Is this a great country or what? :D

boy o boy did this thread die out or what? i guess yamaha is taking care of business? my bike is at the dealer, but no parts to fix! its been there a week. :)

190 miles and no failure... :)

I ordered the parts 3 weeks ago when we got wind it was coming. :)..The gasket is in but no Key....Hope mine is in good condition, if so I'll have an extra.

Before reading this information, keep in mind, I am not a statistician. Also I wish the test group had more numbers in it to validate the information. Despite the small response I noticed some interesting preliminary data. In other words, take this for what it's worth.

Here is the skinney

Production (serial numbers)

From 1091 to 1766 = 100% of the failures in the study group. No failures were reported from 0-1090 or from 1777 or above. The 1766 appears to be a spike in the data. The next highest failure was at 1321.

From 1091 to 1286 = 77.7%

I also noted after reviewing the posts on the bikes that have not failed that the 1000 and above were the first ones delivered to the dealers. Those who received the second shipment of bikes were more like to receive one from 0-1000. With the limited data received, the failure is somewhat related to production number.

Miles to Failure

Of the reported data, 0-130 miles = 100% of the failures. 0-50 miles=55.6% of the failures and 51-100 miles =44.4% of the failures. Based on the limited data, it appears the more miles on your bike, the less likely you will have a failure.

Thanks to all that responded to the post with the information.


Excelnt job describing this to everyone. Everyone should remember this has acctually more POWER than the YZF but it has a heaver flywheel. Second thing is when are 99% of these breaking? It is happening on starting. Before you kicked your ass of to hopefully get enough power in your foor to turn that big trash can piston over, when she kicked back at you it tries to eject you from the sadle. Now you push a button spinning it allot faster than your kick, so when it barks back at you something MUST give. If this tapper is off .1 degree you will get problems. :)

Engineering 101 Every action has an equal and opposite reaction.

Pick up my 03 WR450F tomarrow. :D :D :D

I'm about to pick my 450 up this week.

A friend collected his on Friday, and true enough his key sheared on Sunday.

Our engine numbers are in the 9000's, I would have thought that by now the problem has been solved at factory level, prior to despatch.

Is the lapping of the flywheel the solution?

What worries me is a number of people continue to experience the problem after the mod.

I ride a fair amount of time by myself. I could be up to 30miles from home at any point. If i have a major failure I'm in big trouble. Do I buy this bike or not????? :)

Point of correction.

My friends motor that failed is number 516, apparantly his was from an earlier shipment.

Mine is number 9015.

Are the later manufactured motors fault free?

Well It finally happened to me today ... woodruf sheared. I don't think it was my problem but the nut backed off. (maby it was mine) I didnt check it ... it has been running fine till now ser#1295 :)


As far as I have heard, there really hasn't been any more trouble since the first fiasco. If there was, you would have seen it in here..Guaranteed!. The bike is get down there and pick it up!

Hey David,

Did you happen to ever get that Service Bulletin? I wouldn't mind a copy if available, I'm ordering my WR this weekend and want them to do the checks before I take delivery, if possible.


Thanks for the re-assurance Machster.

I :snore:'ll sleep easier tonight

Well I went to the dealer to find out how long it would take to repair the key problem and he said 2 weeks ... key not in stock. Not liking the idea of this I proceded to PEP boys (remembering that they sold woodruf keys) and picked up a sae version that was the same length and shape. I was a little thicker though. After a bit of time on a piece of emery cloth it fit quite well (15 min max). The lapping, locktite (red), assembly and oil went as planned. I started right up and ran great for 3 minutes and died. The battery was dead after another 20 minutes of trying to get it to start (good spark ect.). Then I finally realised what that selector on the bottom of the gas tank did. What a day! :)

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