YZ magneto cover on WR? No starter=no key failure?

I'm doing everything I can to reduce weight on my WR450, my goal here is to get closer to a trail friendly YZ. I'm wondering if anybody here knows if a YZ450's rotor cover will fit the WR, as I am getting rid of all the starter stuff and without the motor I'd have one heck of an oil leak.

Also , am I thinking correctly that if I remove the starter motor I should never have to worry about the possible woodruff key failure? It sounds like from everything I've read here that if the motor is gone, there won't be the resistance that will break the key if the engine backfires. I have already removed the idler gear between the motor and rotor so I should be safe, right? :)

I'm going riding this weekend in an area where pushing the bike will probably only last for about five feet, not to mention possible endless ridicule by my friend who has a CRF if the old WR breaks down. :D Thanks for any info!!

From what I've been able to learn removing the starter is not a guaranteed fix for the key shearing issuue.

It seems to be more due to the bike having a heavier flywheel, improper torque on the rotor nut and possibly less than perfect fit flywheel to shaft. If you get a backfire the key is designed to shear before serious damage is done to the crank.

Someone chime in if I've got this wrong.

My WR450 sheared @ 16 miles and I've had the Yamaha repair and have about 70 miles since and so far so good.

The YZ cover will not work. I have already tried it. I ended up having a plug machined and pressed in the whole where the starter motor was. I figure I have reduced the weight of my bike by about 18lbs at this time.


Why didn't the yz cover work?I was hoping to use it when i decided whether to keep e-start or not.

The YZ cover doesn't work due to the size of the magnetos and the fact that on the WR the electrics are mounted on the case and fit into the flywheel. The YZ uses the traditional under the flywheel electrics.

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