How do I know if my Woodruff Key is broken?

I was in the Dunes yesterday and my bike just flat out broke. I have an '03 WR450F and I remember a bunch of talk about the Woodruff Key.

-my bike has been hard to start during the last week

-bike ran fine until it died

-couldn't kick it or bump it. Tried towing the thing for a fast bump go.

-changed out the plug and still wouldn't go.

-jumpstarted the battery with cables and it wouldn't turn over.

I dunno....might be the starter, but how would I know if it was the key???

Lemme know. Thanks in advance.

P.S Check out the pic of this in the Pics and video forum


:cry: there is a way to do it is put your hand over the tail pipe and try to start the bike if your hand gets pushed away your key is fine when the key brakes the starter will turn but the motor will not.but it sounds like you have to ajust your valves hope this helps :cry:

When using the electric start it will sound like it's spinning the flywheel but not the motor.When kicking you will get compression but your timing will be out.Mine backfired while trying to start before this happened.I pulled my oil fill plug out and got a mate to kick it over while i looked in at the flywheel.It wasn't turning.Also my wires to the ignition switch broke at the back of the switch.I have heard of others with this problem.Mine cut out when braking but as soon as i hit the gas it went again.The wire would come away at times and it was very hard to find the problem.Valves usually just don't all of a sudden give that sort off problem.And i know this is stupid but HAVE YOU GOT FUEL. Sorry had to ask as you woudn't be the first.

Hope this helps dave

I have fuel. It was backfiring intermittantly while I was kicking had never done that before.

I should probably just take it into the shop. Bummer. Would Yamaha cover the repair if it was the key?

Remove the access cap for the flywheel nut and see if the nut is loose. If it isn't, I'd pull the side cover and look at it.

did the bike get the lap and loctite service early on? yamaha is supposed to cover the repairs, but don't give them a reason not to. find out what your shop has to say before you take everything apart. they may not want you to touch it or your screwed. do some research on the '04 upgrade.

Remove the access cap for the flywheel nut and see if the nut is loose. If it isn't, I'd pull the side cover and look at it.

It might be qiucker to check nut first if it is not loose remove tappet cover and check cam timing marks as per your manual if cam marks still align parrallel with head but flywheel mark is out you have sheared the woodruff key

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