I have a Zenoah 62 which runs perfect on the ground but rich in the air,
rich to the point that pulling back to half throttel stalls the engine,
next i set the bottom end lean on the ground top end left alone as it was fine,
still no better.
The engine is mounted in open air, standerd muffler, the only add on is an intake stack pipe.
Anybody got any ideas??
Cheers