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View Full Version : what dome size?


edz250r
11-29-2004, 07:42 PM
I'm looking to purchase a cool head. What is the lowest mm that you can run pump gas with?
zedicus00
11-29-2004, 08:59 PM
21cc, 20cc MAY b o.k. if u can find 93 oct pump gas but even then i wouldnt chance it.
Roostin250R
11-30-2004, 03:01 AM
I run a 21cc dome on mine with 93 pump gas, runs just fine. Go any lower and I wouldn't chance it.
edz250r
11-30-2004, 07:35 AM
What is your compression with the 21cc dome? I've heard that anything over 185 requires at least a mix of race/pump gas.
Roostin250R
11-30-2004, 04:32 PM
I haven't checked it lately being I recently had my engine builder freshen my top end, however I have been running this set up for several years now with no problems. My builder ( K&T Performance in Roy, Utah) told me 21cc is fine for pump gas but if you drop to say like a 19cc dome then he said you would want to run higher octane.
stocktires
11-30-2004, 09:54 PM
I'm running a 19cc "Powerstar dome". Runs fine on anything actually. I'm now only putting in VP Red, 105 octane I believe.