'03 WR450F Woodruff Key Blues

Well I don't have my WR 450 yet. So I don't have a owners manual. :) Thanks for the info.

a woodruff key is used to position the flywheel onto the crankshaft at a certain position - for ignition timing reasons. the primary gear sometimes has one as well.

good luck

Picked up my WR450 today. The dealer checked out the woodruff key issue. There is a service tech note which tells them to remove the nut and retighten to 47 ft-lbs. <ul type="square"> SM Page 4-81 says 61 ft-lb and this is wrong...

They did it in the shop and also removed the stock baffle. :) It runs great... Started first and every time.. Was worth the wait..

I haven't done mine yet, but I would guess you could put it in gear and hold the rear brake pedal down???

I could be out in left field. Wouldn't be the first time... :)

adamwagar that does work. That is how mine was done. However it works much better if it is put in 5th gear and not 1st.

Mine is 994 and it was torqued correctly. I would still check though. Mine wouldn't E-start with the stock jetting and the snorkel/baffle out. Put in the 160 main 48 pilot and 72 starter jet then it started. I've was putting off the jetting because the 72 was on back order. With the baffle removed does anyone else hear the spark arrestor rattling around ? Didn't know if I should take off the end cap and check for anything.

On the way to the shop to pick up my bike, another TT member called me on my cel phone to tell me about the woodruff key issue. I told the shop owner about it; he was unaware and said go ahead and ride it. I gave it a test ride behind the shop. Landed off a jump, engine died and would not restart (niether kick-start nor e-start). :) Mechanic pulled the flywheel and discovered a broken woodruff key. They replaced the key and torqued according to the loose page note in my owners manual (found it while reading manual waiting on the woodruff key fix). Rode bike another 20 minutes, no problems.

Took the bike to a hare scramble that next weekend. While practicing my starts using the magic button (that's why I bought it!) it back-fired once and would not restart. I drove home, swapped for my trusty old WR400 and was able to make practice Saturday and the race Sunday. (3rd in Sporstamn B, if anybody cares!)

Took the bike to a local shop Tuesday. Another broken woodruff key. :D Crankshaft was OK, but flywheel was a little burred. Shop ordered a new flywheel from Yamaha. Yamaha tech support suggested lapping the flywheel to crankshaft with lapping compound, then loc-tite and torque the nut. Still waiting on the flywheel. We'll see if it lasts.

two keys.....isnt that just peachy. :)

There's more to all this than improper torque. IMHO.

Who has the Yamaha contact info? It sounds like time to throw a fit? Is the re-torque taking care of the problem 100%? Has anyone who has had the problem spot blued and checked the fit? ---Mike

This is the first time we've heard of a second failure. Doesn't sound good. We can only hope the tech torgued it wrong after the first failure, or we are all destined for some long walks home...

I have a hard time buying the improper torque as the cause of a pattern of failure, especially after the second occurrence. Although there seems to have been some attention by Yamaha on the nut torque, they may just be addressing the obvious before looking for a more fundamental problem. Or, they may be hoping for a bandaid solution.

It's interesting that there seems to be bikes that just aren't having the problem and bikes that are failing almost immediately. Maybe a bad batch of machining? If one of the parts is improperly machined, then lapping the parts together will mean that they would likely have to be replaced as a set in the future to avoid the same problem.

Superdave, are you still running stock jetting ? Mine wouldn't even start with stock. I had to add throttle (major no no) to even get it to fire. Then when I kicked it there was the nice backfire. I think it might have to due with the jetting. Be intesting to know if any non-US models have sheared keys. Thank goodness the tree huggers have made our lives easier and safer :)


Could you please tell us the production number of your bike? Thanks.

Went riding with two buddies this morning that have new 450's and after less than 20 miles both woodruff keys failed. That makes a 100% failure rate of all WR's in Memphis as mine makes a total of 3 for 3 in the failure department. There is definately more to this problem than meets the eye. Although mine has run ok since repair I cringe every time I hit the button.

<ul type="square"> It is time for Yamaha to quit pretending these is no problem. We must all collectively contact our dealers and contact Yamaha, and complain very loudly...

Otherwise, 3 months from now Yamaha will be saying they haven't heard of any key problems.... Apparently, they should have put the bike on "production hold", but instead they shipped em. :) I have decided not to ride an enduro this weekend until this problem has been identified as to the cause.....

on a brand new $6000 dirt bike, WE shouldnt have to be lapping the flywheel to the crank. this should be yamahas problem to fix it , not ours. grrrrrrrrrrrrr. :)

we need phone #'s and email addy's to yamaha so we can bitch. um...excuse me.. address our concerns. :D

I am with XR we need some phone numbers, email etc

Yamaha of America customer service, 800-962-7926. If you have had a problem call, let them know that thier bikes are getting flamed on the internet. Maybe that will help get some response. No company wants bad press, and the internet rumors are faster than the nightly news.

In a previous post someone who had a 450 said the flywheel and shaft did not mate properly and they lapped them to fit. Rather than just retorque the flywheel nut, a more comforting check would be to apply prussian blue or another indicator to the parts and see if there are high spots - then you can decide whether the fit is OK or needs some attention. If the taper is not correct on one of the parts you have a real problem - but if the issue is a localized high spot - lapping would be a fix. I don't understand why anyone would feel that reducing the torque on the flywheel nut and replacing the woodruff key is a fix. Unless the under 20 ft.lbs. of over-torque difference is somehow distorting the flywheel taper by forcing it too far onto the shaft, that difference just could not make or break the deal. As noted by others as well, the taper fit does the actual holding - that's why if a key fails they can still run, but slightly off-timed. If you're like me and ride alone, I would check the fit.

Who was it that said we're "drama queens" ? - nice comment, slick. :)

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