RE: Sig Somethin Extra CG
Good luck with the "Something Extra". It is a great plane! I originally came out tail heavy. The first engine I mounted was a Magnum XLS.46. It was ok, but it didn't give me the verticals that I wanted. I switched it out to a Magnum Xl.53 with an APC 11 x 5 prop. I also tried to lighten up the tail. I ditched the support wires on the tail and I also moved the engine as far forward as I could on an engine mount. I have an OS .46LA I have tried to use it on several planes, I usually end up taking it off and mounting an engine with some guts. They are a good engine, just kind of so so on the power. I may make another "the Hots" and try the LA on that. it's total fly weight is only 3.5LBS.
It may be a good deal for you. Good luck with it.
Frank