Zagnut,

The shaft on the engine I'm looking at isn't treaded all the way down... It sticks out of the case about 4.5 to 5 inches and is tapered slightly at the base (shere the keyway is for the flywheel). It is threaded about 1.5 inches of the end, is 'noched' on one side (not round) and it bored and tapped in the center.

So If I understand the concept correctly I need something that will go over the shaft all the way to the fly-wheel, to hold the flywheel in place and come out far enough to make sure my prop is clear of everything, and make the prop bolt tighten up to hold everything together. right!? and of course all has to be balanced and strong enough to take the abbuse.

essentially one big spacer!... seems simple enough!
What am i missing. (some seem afraid of this if its not bought!?)