Hello,

Running CoolPower 30%, OS F plug, APC 13/4W prop. Plenty of ventilation. Engine starts fine and idles fine. I let it warm up at idle then bring it up to about a 1/4 throttle and hold a moment. Engine runs fine and sounds good. When I try to slowly open throttle all the way, at about 3/4 to full throttle the engine runs fine but then starts to detonate or pre-ignition and stops abruptly. I'm not sure what its doing, but it does not sound good at all, as if something was knocking it. I bring it back to idle or less than 1/2 throttle the engine sounds good again. I cannot seem to run it at full throttle. The engine has about 15 10 minute flights on it and I have had no problems till today. I have the high end needle out about 2 1/2 turns and have not touched anything else. I did turn the regulator a 1/4 run out thinking it was going lean during transition. I see plenty of smoke during transition but much less as full throttle.

John Sabini
19 Wittman Lane
Brentwood, NY 11717
516-770-2480

I don't think it is either detonating or going lean. Try running the HS needle in to about 1.75 turns and tell me what happens. I think it's too rich.