Help! My WR is dead!

Hello, I'm from Norway and I bought a 2003 WR450F just one week ago.

The bike ran great when I got it, but on the second trip in the woods I stalled it driving up a rather steep hill. Nothing to worry about you might think! After that the bike did NOT start and I had to call for assistance to get it home with me.

The bike does not start at all! I have tried everything I can think off! First off a new spark plug. Then I tried to run a coil and a cdi box from another bike (my brothers 2004 WR450F) I have checked all the plugs and connections on the bike and cleaned them. The spark is ok and the sparkplug gets wet when I kick it with full choke. It has fuel and ignition and everything looks OK!

But it won't RUN?!!!

Is the spark yellow or blue?

Have you tried to bump start it?

The next thing I would check would be the compression. Do a normal compression test or better yet, a leakdown test. I've heard of the odd case of valves sticking open a little.

The spark is blue. Did read about the woodruff key and rushed out to the garage to check it out.. It's not that, it is tight and fine! Have only compared the compression to my brothers 2004 and I cant feel any difference on the two bikes when I kick them... But I am not sure.. It could be the case..

Not sure about anything anymore:ride:

Thanks......

Oskar

try checking the valve clearance

The spark is blue. Did read about the woodruff key and rushed out to the garage to check it out.. It's not that, it is tight and fine! Have only compared the compression to my brothers 2004 and I cant feel any difference on the two bikes when I kick them... But I am not sure.. It could be the case..

Not sure about anything anymore:ride:

Thanks......

Oskar

What exactly did you check on the woodruff key? The key could have sheered, and the flywheel will still appear to be tight, but in fact it has rotated out of position. Compression test might be difficult with the auto-decomp exhaust cam.

I personally "speculate" that the flywheel has moved out of position. Good luck mate.

What exactly did you check on the woodruff key? .

I repeat that question.

When the woodruff key "failed" on my 2003 WR450, the key didn't shear. It only bent a little bit, and you couldn't even tell that it was bent with the flywheel still on. After I took off the flywheel, and found the bent key, I would estimate that my flywheel hadn't moved any farther then 0.030 of an inch around the shaft.

Well I went out in the garage again and started checking the valve clearance and, well what can I say.... You guys are 100% right. When I had the TDC mark in the inspection hole, the piston was far from the top! So it looks like it’s the woodruff key after all. The flywheel sits tight on the shaft and now I need to get me some tools to get it off. Well it‘s a relief to know what is wrong and knowing that it's not long before I can switch to spikes and start doing wheelies on the icy lakes and roads!

Thanks a lot for your help guys!

Best regards

Oskar

I would contact Yamaha as they should be paying for the repair.

Good catch, this is what makes this site so great. Lots of people with experience.

Well I went out in the garage again and started checking the valve clearance and, well what can I say.... You guys are 100% right. When I had the TDC mark in the inspection hole, the piston was far from the top! So it looks like it’s the woodruff key after all. The flywheel sits tight on the shaft and now I need to get me some tools to get it off. Well it‘s a relief to know what is wrong and knowing that it's not long before I can switch to spikes and start doing wheelies on the icy lakes and roads!

Thanks a lot for your help guys!

Best regards

Oskar

I would suggest that you upgrade to the re-designed 04 starter mechinism parts. That will fix the reason why the key sheared in the first place. Do a forum search on the subject. Some of the TT guys here did a good writeup on how to do it. Well worth the time and effort to upgrade! :worthy:

.... When I had the TDC mark in the inspection hole, the piston was far from the top! ....

The fact that you did not mention anything about the marks on the camshafts makes me think that you were not at TDC. WHen you checked this, were the punch marks on the camshafts lined up correctly? Were your cam lobes pointing at 10:00 and 2:00 when the TDC mark was visible in the inspection hole? The correct procedure for checking this is in your service manual.

If you do have a woodruff key issue, definitly upgrade to the 04 starter parts. Do a search for '04 upgrade' or 'starter upgrade'.

Also, you do not need to buy an 04 case. There is a Yamaha bushing you can buy to press into your 03 case.

Tom E.

Well now the bike is fixed. I removed the flywheel and the woodruff key was cut in half! No damage to the tap or the flywheel :thumbsup: I have a new starter and starter clutch (not sure if it's a 04 starter... have to check that out... it was fixed two weeks before I got the bike) Got a new woodruff key and gasket on the warranty. The technical manager at Yamaha Norway said that I should use some valve-compound on the flywheel tap and flywheel to make the contact area more even and then he said that I should use Locktite 648 to glue the flywheel to the tap! (Sounds like a "in the pit, last chance" kind of solution to me :-) I think it will be interesting to get the flywheel off next time around....

Anyway it's good to know that there is help out there...

Oskar

Have got a rotor puller tool

Yamaha want £49 i can do it for £25

Want it ?

email john1000@tiscali.co.uk

yes in the UK

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