Good ol trial and error huh? haha. Everyone on this forum will recommend the os A3 glow plug. its a hotter burning plug and it works great man. They're like 4 bucks at your lhs. As far as your fuel goes, im not sure. I run 20% nitro and 12% oil and have never had a problem. I guess if you're gonna stick with that fuel just keep it little more on the rich side, low and high speed needles.