Has anyone tried to make a reduction prop drive for a conversion engine?

My Poulan 54cc turns about 6900-7000RPM with a 22-8 prop. But that engine is rated for over 12,000RPM in the saw. Imagine the prop you could swing if the engine RPMs went up to 9000 or 10,000RPM and you could swing a 24 or 26" prop at 7500RPM!! The thrust would be unbelievable.

The reason I'm curious about this is because I don't believe that my Poulan 54 engine is -- up in the "powerband" at 7000RPM. I'll bet it makes it's best power at 9000-11000RPM.

I was thinking about a belt driven reduction drive. Remember the old Byron Mustang with the belt drive unit?

I don't know a thing about machining these kinds of parts. I would think that a gear driven drive would require some sort of lubrication system to keep things from heating up and seizing.

I know that running the engine at higher RPM's will make it wear out faster. I don't care about engine life. These conversions are so cheap-- I could build a new one every year if I had too.