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Discussion Starter #1
I have a ESR race gas dome which they said is normally 190-210 psi. I've been running straight sunoco 110 in it with 40:1 ams oil. I just did a compression check and I was getting about 180 - 185 psi after kicking it over about 10 times with water temp up to about 130 from just idling in the garage. I'm close to sea level if that matters. Should I switch to a 50/50 mix of race/pump gas? What is the compression range for 50/50 mix of 91 and 110?
 

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Discussion Starter #4
what is it with the motor cold??
I did't check the compression with the engine cold. I'll check it cold tomarrow. The honda manual said to warm up the engine first.
 

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i have between 180-185 psi and i run 92 or 93 what ever super is at mobil, and i mix at 32:1
 

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Discussion Starter #6
what is it with the motor cold??
Just checked. It's about 190 psi cold.
 

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you will be with a 50/50 mix. might even be able to get away with just straight super but it is a risk.
 

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well I run 50/50 of c12 and 91 at 36:1 with 185psi cold. Run's alittle cooler and smells great.. :p
 

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Discussion Starter #9
I talked to ESR today. They said they set up their race gas domes at about 190 psi. They recommended that I keep running straight 110 race gas since I ride in the sand about 99% of the time. The heavy sand and paddles puts a lot of load on these engines. Plus, it's been running great.
 

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i just seized piston twice in a month because of pump gas. not cool my fault though. hard to find fresh race gas in the winter. i do live 30 min from iron pony though they have it.
 

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I had the same type of question a month or so ago. I have a PSI 425 powervalve cyllinder on my quad. I got it ported by a local builder and he said that I should be running straight race gas with 165lbs compression. I thought he was on glue! After doing a bunch of research, I found out that there are more factors involved with what type of fuel your machine requires other than compression. One of the major one's is exhaust duration. The more degrees your exhaust is open, the more heat your exhaust stuffs back into your cylinder, requiring a better quality of fuel. Be careful when people suggest what gas to run for your machine, they may not have all the facts!!!
 
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