ORIGINAL: FA82Showtime
ya, i was just wondering if it was a tank problem, anyhow the fuel i use is omega 15% in most of my planes some power master also
the 61 has 12x6 APC prop and i use a O.S #8 plug
I use the same fuel. You might try a Hanger 9 Super plug. It's actually a 4-stroke plug. I saw a marked improvement over the OS#8. It costs more, like $8, but I haven't fouled one yet and I had my engine running stupid rich for a long time..... (Long story, but now I've got it tuned it properly.) When I was trying to iron out my engine issues, Horizon tech help told me the H9 SP was the way to go.
I don't think the plug has anything to do with your symptoms, but you might consider the plug when you get it all ironed out.