I have a Fuji 50 EI that has been converted (not by me). It seems to run pretty good but the problem Im having is massive vibration at idle. I have balanced the prop and check about everything I know of. Is there any way to check the runout on the prop shaft? And can you think of any other reasons I may be having so much vibration at idle?......Thanks Johnny

If you don't get much vibration, so to speak, at high RPM, then it's not likely that the propshaft is out-of-round or off-center. Balance would be OK, too. Likely, it's the somewhat rougher running typical of many engines at idle. You may be trying to idle too slowly, which causes the engine to fire unevenly, and that makes the vibration. You may have to accept an idle that's a few hundred RPM higher to smooth things out.