Crankshaft/Key issue

[benbackwards]

Hey all,

So while replacing the stator on my 1980 KDX 175 come to find the key was part of the timing issue as it was bent and was scoring the flywheel and crank. I went to the local hardware store and bought a key that ALMOST fit perfect (I now know the error in that decision). Got it back together and the bike ran great for two hours or so. Then i could hear a horrendous noise coming from the crank. Opened her up and the key had practically melted into the crank so much so that I can't get another key down into the groove. Suggestions on how to remedy the issue would be great, found a crank online but for $600!! I'm sure there is a repair option as opposed to replacing the crank.

[KDXGarage]

Welcome to kdxrider.net. Thank you for joining us AND participating.

Dremel with a diamond bit? carbide burr bit? square file to finish the job?

You're not the first and won't be the last to figure out that a hardware store key won't do too well.

[benbackwards]

Thanks, may give that a try. Debating on taking it to a local machine shop and see what it would cost for a professional to handle it...i don't want to fudge it up even more.

[KDXGarage]

Go gentle at first. Back off if it doesn't seem right. Don't be afraid to get someone else to repair it if need be.

[pumpguy]

The key just sets the position of the flywheel relative to the crank shaft. Its the tapers and how tight the nut is that actually do the holding.

If you have a sheared or damaged key, the flywheel has shifted on the shaft. Sounds to me like you have damaged or mis-matched tapers either on the shaft, the taper bore of the flywheel, or both.