RE: Can you run a gas motor with no muffler?
I have a DLE 55 with a J-tech Muffler and a 19x8 Belia prop on aTF 1/5 Mustang and it flys great! I think you will have plenty of power with the zdz80/jtech muffler/ 4 blade.
That being said, i would not run a gas engine without a muffler. You need the back pressure for the engine to runner properly.
Chris923