Compression 215 Help Please

[RYANHENRY]

running a wossner 71.94 piston and cool head 21cc dome and my compression is around 215-220 how can i get it lower to run premium pump gas 92-93 octane i know that there is one more dome size 23 but really would that make a diff in the compression my piston got to hot on the exhaust side and locked the rings into it burnt lil bit on top lil but of a hole again on the exhaust side from what ive read sounds like to much compression for pump gas and detonation was happening ive also hurd running another base gasket but i dont know if that would really help am i pretty much just screwed and gotta run high octane gas?

[C-LEIGH RACING]

If you could get PURE gas, not this crap sold today with ethanol in it, a 23cc dome would help some.
Need to get it down around 180~190 lbs for prem pump gas.
What if you used a 50/50 race/pump gas mix & a little larger main jet to keep the piston cool.

It really sounds like you maybe done solved your high compression problem with the half seized piston & stuck rings.
Neil

[machwon]

You could get someone to make your 21cc dome larger. You can always go larger, its a lot harder to make it smaller. Be careful when going by the compression guage. Gauges can vary and exhaust port height can really make things different.

[C-LEIGH RACING]

Yep, you sure can cut that old dome, I clean forgot about that.

I guess I was confusing myself while replying, from thinking to much of the effects of him trying to use that ethanol pump gas.

It looks like its going to be a bigger job than I had figured, trying to stress the point of not using pump gas, because that ethanol is death to a two stroke.

The day of pulling up to the pump, fill the jug & go riding all day, is a thing of the past, specially if any performance mods done to the engine.
Neil

[machwon]

Actually I've been thinking about building an ethanol motor and that would be an option here as well. E85 fuel is around 105 octane and is a cheaper substitute for race fuel. It's just not as readily available in the upper parts of our state. Perhaps if you had an E85 vehicle you could siphon the tank for more fuel. My concern is the jetting and trying to get a jet large enough on a Keihin carb without using drill bits would likely be a problem.

[RYANHENRY]

thanks guys and i also forgot about when i was running a cometic 72-74mm head gasket the the gasket was a lil ways past my bore and when the explosion was going on it had forced the gasket past the water water holes slightly and blew my head gasket that was the first time i put it together what i did was i found a copper gasket that was same size as my bore pretty much but the only thing was that is was much thinner like .025 but with that one it isent so close to the water jacket but what i think im going to do is get this other cometic head gasket like my last one but get the one that is same size as my bore there alot thicker so that will help to on my compression problem