ORIGINAL: joeshmoe_44883
another way to gain power is getting rid of as much parasitic drag as possible. for instance, see if you can find ceramic bearings to replace the cheap crappy steel ones. the difference is like going from a bushing'd engine to a ball bearing'd one. polish the crankpin and wrist pin, put a ceramic coat on top of piston and inside the head. the less energy that is soaked up by the head is more energy pushing down on the piston. its a bit of work, but like everything else its all in the details.
I've used ceramic bearings, and they do let the engine turn a bit faster, 150/100 RPM is what I saw. If your racing, and you want every little bit out of it, then fine, but I found that I was changing bearings every 1 1/2 gallons or so. I've heard about ceramic coatings on top of piston and inside the head but never seen it done on our small sport engines.