From what I have read, it seems like the 11 mm carb is the way to go. I am still kinda digging around looking for a better carb than the Zama.
I hadn't planned on using the original sheet metal muffler, I found an old weedeater intake manifold stub that fits the exhaust port and fits 1/2 in. copper plumbing. I figured on using a modified butane can for a muffler.
I can't believe 2 hp! really? wow. Mine won't come close to 7000 with the 18x8 with the Zama carb. I need to finish the engine instalation in the plane first so I can run the engine again and experiment.