Just to interject my opinion based on the whole reed valve and windowed piston conversation. If more power is your goal, skip this entirely, especially on a piston port engine. Every single engine dyno I have seen generally shows no gain, and usually power loss, when running a reed with a windowed piston on these little engines. This is especially true of engines that have very small intake duration and/or higher ABDC intake opening figures combined with very low transfer duration and blowdown numbers. Aka, engines not turning a lot of RPM with very weak/low intake volume.
You can see this with even more powerful piston port engines like the Phantom 85 where deleting the OZ reed and windowed piston increased the horsepower half a point, and the Phantom has way more aggressive port numbers than a typical china doll engine.
The counter argument to this would be that in some cases you do see an increase in bottom to mid range torque, but it often isn't much either, and the headache of getting a G2 reed to seal is something I don't find all that fun. Plus, every gasket sealed surface is adding another failure point for intake leaks.