WR rotor (flywheel) allowable damage?

Based on the amount of threads I have read with failed woodruff keys and starter clutch problems on 2003 WR 450s, I figure someone has tried the following and can lend their opinion:

How much damage on the inside surface of a rotor is too much? I realize the magnet generates current from rotating around the stator. So how much imprefection would allow a WR still to operate?

I had two bolts that tie the starter clutch to the rotor back out then shear off and grind around inside the rotor a bit. Stator is toast. Damage to rotor is primarily in the inner 10% of the race near the radius to the bolt face.

Dealer wants $100 for the rotor and I am inclined to throw this one back on with a new stator...just don't want to have to tear into the motor again. Curious if anyone else has experience with damage to rotors and success without replacing.

As a side note, mine had the dealer retorque fix, which kept the woodruff key from failing. Not quite sure why the starter clutch bolts backed out (2 sheared off, other 4 all hand tight).


A few grooves from the bolts is no big deal. I would not worry about it.

What happens to the bolts is not that they simply shear rather they get loose, the heads hit the stator which in turn, shears the heads off.

Would anyone recommend against honing the inside of the rotor with sandpaper to take the high spots off?

Just clean it up enough so it wont damage the new stator. Make sure to lap the the flywheel taper and locktite on.

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