Engine Noise - Crackling
I have a new plane - a supersporster with a new 61 fx (~15 flights so far). When I get her into the air, the engine makes a crackling, sort-of-popping kind of noise. It sounds bad. Even one of my flying buddies who only flies electric says the engine does not sound right. As far as the mixture goes (the high speed needle that is), it seems to be okay - I set the mixture before each flight (~12,000 rpm). She idles good and does not cut out during flight. The engine sounds fine on the ground.
Why does my engine make this strange popping noise? Is it preignition? Maybe the wrong plug? I wish I could record the noise and play for you here as it is a very "popping" crackling noise.
Any help is appreciated!
Thanks,
Boots