I will have to contact Mr. Bennett and see if he can make the prop hub with a magnet in it. On the front of the engine there are 8mm threads for the nut/hub and then the shaft tapers larger with a key way. Where do you find a magnet to install in the prop hub? I'm afraid this is getting way over my head. By the time I get all this custom work done I could have probably bought a 20cc engine. I am trying this 15.9 for my 60-90 sized corsair. it should be about the equal of a 1.08 2 stroke.