For those of you thinking about a gas engine,, the Zenoah g-26 is a great engine for this plane,, heres pics of my installation,,,, The engines really not broken in yet and it still hauls ass. The weight is almost perfect, I actually had to add a few ounces to the nose to make it slightly nose heavy.
I'm using the BH Hanson G-26 converted to electronic ignition, Hand starting is a breeze..... Awesome sound with the pitts muffler.
see the pics here www.rcsmp.com/mustang.htm