ORIGINAL: dirtybird
A two cycle gasoline single cylinder engine will vibrate. There is no way to get around it. Your installation may have a resonate spot at low rpm that exaggerates the problem. Make sure the engine is secure and avoid that RPM if possible. I doubt if a small spot of epoxy on the spinner has anything to do with it.
seems logical. The vibration is huge at low RPM. The whole plane shakes hard. If I up the idle, then it becomes too fast for landing.
What about the spark plug? It is the same one that was used during engine brake-in. I opened it the other day and it was black and replaced it with a new one.
One more thing I did which I haven't tested yet. The muffler was leaking small amount of black burnt oil. I removed the muffler and installed a gasket and put it back on again.
Now I have done two things: New plug and muffler gasket. So, if the vibration reduces I would not know which was the fix
