Raising compression

[Chainlube]

I'm curious as to how much compression these 66cc China girls can handle. I understand that they come stock with just 6:1 compression. I've read of people using a pop can to make a head gasket. How much would this raise compression? Would there be problems like the piston hitting the plug? Also if you sand smooth the head and jug surface, that could also raise compression. How much compression would be too much for these engines to handle? I've also read of people using no head gasket. Wouldn't that cause problems? I'm thinking more compression=more power, but I wouldn't want to break anything.

Don't expect to get too much out of it, to really raise the compression everything has to be machined and then the bottoms will break.
Put your engine in a vise and bolt the cylinder down sans head, not tight, just firm. Turn the engine over until the piston is at the top and post a picture of it. Measure the distance from the deck to piston and the thickness of your head gasket, that will be close to your squish. Should = .7-.8mm.

 

[Whitewill1412]

Don't expect to get too much out of it, to really raise the compression everything has to be machined and then the bottoms will break.
Put your engine in a vise and bolt the cylinder down sans head, not tight, just firm. Turn the engine over until the piston is at the top and post a picture of it. Measure the distance from the deck to piston and the thickness of your head gasket, that will be close to your squish. Should = .7-.8mm.

That's what I was worried about. Raising the compression being too much stress on the bottom end. I don't have a vise or measuring tools.