I'm working on a Poulan 42 short shaft conversion with EI. Can you post some designs for your
prop shaft adapters? Or maybe a source to purchase one. I have a small lathe so I can make one myself. It seems that the there may be an issue with this thing rotating off of the crank shaft if there is not a positve lock, such as a key in the 1/8'" slot that is cut into the taper.

Few people do this they just use Locktite

yep, cut a taper in the end that would go to the crank, cut it a little shallower than it needs to be (just a little), that way you are pushing on the biggest part of the crank, make a ring for the magnet to mount over it, it works easy, if you want to see what I made up go HERE, I just have the 7x12 lathe and worked with what I had...

Thanks for the info. I like the idea of a seperate ring for the sensor so that you can set the magnet location. I assume you just put a set screw in the ring to stop rotation. Do you have any problem tightening the prop or the adapter as it does not look like you have a way to hold the shaft during tightening.

take the pull start rope out of the starter housing and stuff it in the cylinder through the spark plug hole (you can use another type of rope, but the pull start rope is usually handy), use this to keep the engine from turning when tightening the prop adapter, and I just do that with the prop mounted to it for more leverage... a little blue loctite on the crank threads for good measure

and yes, one set screw to keep the ring from turning