Though not gas (glo) I've seen people wear out thrust washers literally cranking engines for what seemed like hours with a starter ..... and still no success. 100% owner induced problems I might add but good entertainment watching them when they won't take even simple suggestions. Thankfully have not seen such a thing in a long time.

Just finished 19 flights, 10 min. each, on my DLE-35ra powered Extra 360. The engine started running rough so I landed. I thought there may have been something complicated going on to cause the rough running engine. When I took the cowl off, the muffler fell out. Never had that happen before on a DLE. I checked the engine and muffler mating surfaces and they seemed to be pretty rough. I used a fine toothed file and stone to smooth them out. Used the Grey Gasket maker to seal the muffler and put it back on. Hope that fixes the problem.

Make sure you are getting adequate airflow to the back of the cylinder, muffler and carb area of the engine. In many cases, the rear mounted muffler gets very hot behind the cylinder and that leads to the loose muffler problems. Radiated heat can cause carb tuning problems. Rear exhaust engines are great in many ways but they create their own unique problems that side exhaust engines don't usually have.

I thought it interesting that many of the new RCGF rear exhaust engines are coming with a wrap around baffle ..... I assume to help cool the back side of the cylinder.