'03 WR450F Woodruff Key Blues

32 miles on my new WR450F, and bang! There it went, the woodruff key sheared. Broke the

left crankcase cover at the starter gear too. Good thing it has a 30 day warrenty! :)

On the upside I have not seen anyone else have a repeat problem once the key is repaired properly. Not what you want to hear right now but my bike has been awesome since repairs were completed. Hang in there and get your jetting dialed in with the downtime.

Thanks "utvols" for all jetting info. Can't do any jetting right now because bike is at mtc shop.

I did install 48 pilot, dealer didn't have the correct main or starter jets. Starts much better now.

Thanks again for the info!

How bad is this key problem? It seems like 50% of the WR450 riders have had failures. What is Yamaha doing about it? :)

Here we go........... :)

They are fixing them. If your dealer is worth anything at all they will not charge you for this. Its a 10 minutes fix and costs them a spot of labour and a $12 part. There have been zero reports of a second failure, so I would suggest you just stay close to the truck for the first 40 or 50 miles of riding until you're sure whether or not your bike is a problem child.

Please dont stir up another pissing contest. Either you want the bike or you dont but 99% of the readers in this forum have already made their decision on the matter. We are aware of the problem as is yamaha. With all the hype on this bike there will certainly be fixes forthcoming for the bikes that shipped. And with the bikes yet to ship I'm certain these fixes are already done.

In another thread you mention that the 'production problem' you were told about from your dealer is this same issue. Considering you've also said your dealer made that up to stall you / soothe you until his march order arrived, I'm a bit confused. Has the fact that there is a service issue on some bikes somehow made his statement factual? Have you forgotten that a number of people made many attempts at verifying a production hold / call back at local, national, and international levels and all found it to be false?

Gah, now i've gone and taken the bait. :)

Buy it or dont, mate.



I had the same problem. . . Sheared the key. My dealer fixed it after they called Yamaha. According to them, Yamaha told them to replace all woodruff keys right out of the box and make sure the proper torque is applied.

No Charge and I'm back riding. :)


Can you give us some details of your setup prior to shearing? Such as:

Did you retorque the rotor nut? If so, what to?

Were you running stock jetting?

Did it back fire when it sheared?

Thanks in advance :)

The woodruff key is on the left (port) side isnt it. When you pull this cover off do you lose much oil, because the oil fill is on this side. Should I wait till next oil change or do you think it is a do it now deal have 41 miles on new bike and want to ride tomorrow and if I mess with key and oil wont have time to ride and the weather will turn bad and my wife might catch me and the dog etc. etc.. Seriosly, I do need to plan for at least adding oil dont I. Thanks Tim

Lay the bike on its side.

i leaned the bike at about 45 degrees against the wall of my shed and didn't lose a drop.

Okeedokee. Tim


This is what Hick and ThumperWR450F recommended you do:

Flywheel cover off

You won't lose any oil this way. :)


I wasn't sure how far I needed to go over so...better safe than sorry! I saw Ferry's mechanic do this at a supercross last year. :)

Yeh but Yeh but but I have this expensive hydraulic stand and you say I need to resort to something as primitive as that. LOL. Thanks for the Help. Tim

According to the owners service bible on page 3-19,you can gain access to the Flywheel mounting nut by removeing the straight plug.I would assume the Flywheel compartment is isolated from your oil.I could be wrong about the oil but it makes sense to me that the Flywheel should be able to spin without the drag of 20w-40 interfering with it :)

you can get to the flywheel nut, but you cannot hold the flywheel to torque it, any suggestions. has the gasket on the cover been breaking. do you use a strap wrench to hold the flywheel.

Oh yes, how far up the production run will this occur my last 4 digits are just under 1100

What is the woodruff key. If the dealer don't check it, can the average Joe do it himself.

point one- it's on page 4-78 of yur manual.

point two - if you do not know what it is then you should take your bike to a dealer.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now