Magneto Flywheel to Crank Key Slot

New here and this is my first post so have patience.

I tore down my Puch E50 engine after gas leaked in over night causing a slight hydro lock scenario (piston ring broken, angry noises made) and discovered the nut that holds the magneto to the crank had backed off until it was grinding on the cover. The woodruff key has wallowed out both the slot in the crank and the slot in the magneto flywheel.

Treats does not have a magneto (points setup) flywheel in stock. I am wondering if I can just put it back together as is and put some thread lock on the crank threads? Will this hold it tight or should I just pony up and replace the crank and put cdi in?

I don’t really want to go the jb weld route as I foresee wanting to take it apart again in the future. Thanks in advance.

Re: Magneto Flywheel to Crank Key Slot

You might consider lapping the flywheel to the crank taper . A medium lapping compound should do .

It's a bit tedious , but , the results should be satisfying .

Re: Magneto Flywheel to Crank Key Slot

You can dremel a slot and fit a half moon woodruff key from an assorted kit found at Harbor Freight or various other places.

Re: Magneto Flywheel to Crank Key Slot

The key is more for alignment than holding power, taper fit is more than sufficient to hold the flywheel in position. Lap the tapers if it it damaged, you need at least 1/3 width contact to secure the flywheel's position. When you assemble align the flywheel to the crankshaft as best as you can and torque that nut well.

Re: Magneto Flywheel to Crank Key Slot

u might get another magneto off buy sell, atleast having one side good woyld be a good be a good start.

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