"Lou" wrote in message Thanks, I see quite a bit of airboat motors for
sale at 1/4 of the
price of aircraft. I plan on rebuilding anyway, so I figure why not?

Keep in mind that airboaters are not restricted to approved means of
repairing things. For example, airboaters can fill a cylinder head crack
with silver solder. That works for a while and then they radio for a tow
back to the docks. Would you have the same option of getting a tow if you
were flying behind that crack? Airboaters can install and operate propellers
that have problematic harmonic vibrations. The accumulated fatigue cycles on
the crankshaft may not lead to failure until you are flying behind that
crack. An airboater can limp home on 3 cylinders. Can you? It may be a good
bargain, but do yourself a favor and do a teardown.

D.