RE: Honda GX-31 and Giant Eindekker??
Well, I put some more running time on the Honda on my Eindekker, fine tuned the engine, and changed to an 18 x 6 APC prop. That seemed to make it come alive. It turns the 18 x 6 at 7700 rpms, and pulls the big Eindekker around very nicely. Loops from level flight are no problem, it climbs well, and it takes off at less than 1/3 throttle with it's super light wing loading. Straight stack exhaust sounds great and not too loud. Neat project and I'm happy. I'll get some more pics posted when I get back home after Turkey day.
AV8TOR