ORIGINAL: earlwb

Well, the last new Fox .60 engine I bought and ran, worked pretty good right out of the box. I normally just use 5% nitro glow fuel, so I typically don't have the problems that others do, trying to use higher nitro content glow fuel in the engines. I ran a few tanks of fuel through it with a 11x7 prop and the stock muffler. By then it was loosening up pretty good. So I put on one of my Performance Specialty tuned mufflers using a bridge adapter I made. The engine ran as good as my Rossi .60 engine does.

I like to heat cycle the engines when I break them in, I run it for a while, then let it cool off, run it, cool it off, and so on several times. The first run is extra rich and I don't try to lean it out much or run it full throttle either. Then on each subsequent run I lean it out a little more. Eventually it gets to where it'll hold full throttle good with the needle set a little on the rich side.