Just reading your posts, here, and remembered that Fox has developed and are marketing a .50 gas engine. That would certainly get you out of the gooby mess on your airplane. I must also do a little PR for Fox, I had some trouble with a 3.2, so I sent it in, and they fixed it cheap, the engine was 2 yrs. old. They are a good company that stands by their engines. Here is the link, check it out, 10,500 rpms on a 11x 7 is strong!
http://www.foxmanufacturing.com/inde...db10b45c8cbfe8

I hope you don't have to cut and paste, but it's worth a look.