I haven't played with 1/4 scale gas at all, lots of experience with glow, then electric because after 20 years of flying glow it was still a pain and electric had come so far. But I always wanted to build some big birds, since I got into RC back in the late 70's as a kid. I have also always been facinated with the weed eater type conversions, and lately the 4 strokes in particular. I do have a great deal of experience in building high HP car engines, my daily driver is an STI with 463 at the wheels, but only so much of that translates to a 31cc single cylinder. Timing advance on a forced induction engine is a huge factor in output. In fact the majority of tuning is trying to get the timing just right accross the rpm range to max out the timing within the 93 octane's limits. The same engine at it's max can go another 25% just by running 105 octane race gas. I run a small fuel cell in the trunk that is filled with 105 and 93 in the tank. The tank switch is actuated when the ECU map is switched from a lower boost and ignition map to one with more boost and a more aggresive advance. Applying my experience there to this is a challenge. I did find a place with spare pistons for $28, I may have to get one and so some buildup of the dome.