whats everyone running with a pump gas dome?

[dirtyd]

I have an ESR 310 TRX9 port with a pump gas dome. I'm just wondering what octane fuel everyone uses with a pump gas dome. I have been running a 50/50 mix of 110 and 94 octane to be on the safe side and wonder if I could get away with just the 94. I have a Sunoco station right by my house that has 94 octane but I have to run around town to get race fuel and sometimes they don't have it. I thought that that I read awhile back that some still used race gas with a pump dome. Or would mixing 75/25 premium/race be enough. Just trying to see what others have had good results with.

[F-Red]

You probably already know, how we feel about pump gas. Not the best choice. I use Sunoco Supreme 112 with a gas dome. It is available to me and reasonably cheap. Overkill yes, but I know what I'm getting! :loyal:
It's Devil in a can! :onthego:

[pinned250r]

I am in the process of weining off 110..for strictly cost reasons. once this top end goes, i will be putting the 310 on with pump gas.

[rablack21]

I have an ESR 310 TRX9 port with a pump gas dome. I'm just wondering what octane fuel everyone uses with a pump gas dome. I have been running a 50/50 mix of 110 and 94 octane to be on the safe side and wonder if I could get away with just the 94. I have a Sunoco station right by my house that has 94 octane but I have to run around town to get race fuel and sometimes they don't have it. I thought that that I read awhile back that some still used race gas with a pump dome. Or would mixing 75/25 premium/race be enough. Just trying to see what others have had good results with.

I ran my ESR 310 pv off of 93 octane pump gas (no ethanol) for several years before switching to 110 fuel for racing. I never had a problem running the 93. It's not really the octane issue that you are referring to; it the cleanliness of the fuel and the lack of ethanol. Race fuel is handled very carefully to maintain it's high quality. Some gas stations don't take the same care in their pump fuels. Some gas stations have old rusty holding tanks under the ground that leak and may get water in them. Plus, they may be buying ethanol blended fuels. So there is a possibility of poor quality pump fuels versus that of race fuel. However, if you find a gas station that sells non ethanol pump gas and the gas station doesn't look like it's been there since world war 2, then there is a good possibility their fuel is fine. I found such gas stations, and that is where I used to buy my 93 pump gas from for 3 plus years or so without any issues.

Note: Worst case scenario, if you have to run ethanol pump gas because you can't find 100% gas anywhere, make sure you use a fuel additive that prevents phase separation and prevents gum and varnish formation inside the carb. Those are the main issues involved with using ethanol based fuels, especially in two strokes.

[Jerry Hall]

I am in the process of weining off 110..for strictly cost reasons. once this top end goes, i will be putting the 310 on with pump gas.

The engine will not eventually get use to running on lower and lower octane fuel as time goes on.  You will eventually find what the minimum octane fuel your engine will tolerate with how you are riding it when the piston fails due to detonation.

[pinned250r]

The engine will not eventually get use to running on lower and lower octane fuel as time goes on.  You will eventually find what the minimum octane fuel your engine will tolerate with how you are riding it when the piston fails due to detonation.

Oh thanks for the lookout Jerry. I guess i worded it wrong, I am not simply weining it off by putting less and less 110 in it, i am setting up one of my spare top ends for 93 rather than 110.

As for my current set up on 110, that will remain on 110 as that is what it is built for.

[udontknowme]

I ran my ESR 310 pv off of 93 octane pump gas (no ethanol) for several years before switching to 110 fuel for racing. I never had a problem running the 93. It's not really the octane issue that you are referring to; it the cleanliness of the fuel and the lack of ethanol. Race fuel is handled very carefully to maintain it's high quality. Some gas stations don't take the same care in their pump fuels. Some gas stations have old rusty holding tanks under the ground that leak and may get water in them. Plus, they may be buying ethanol blended fuels. So there is a possibility of poor quality pump fuels versus that of race fuel. However, if you find a gas station that sells non ethanol pump gas and the gas station doesn't look like it's been there since world war 2, then there is a good possibility their fuel is fine. I found such gas stations, and that is where I used to buy my 93 pump gas from for 3 plus years or so without any issues.

Note: Worst case scenario, if you have to run ethanol pump gas because you can't find 100% gas anywhere, make sure you use a fuel additive that prevents phase separation and prevents gum and varnish formation inside the carb. Those are the main issues involved with using ethanol based fuels, especially in two strokes.

if their tanks leak i would hate to see the fine they would be looking at

[rablack21]

Most of the time the tanks don't leak, but they due tend to become "unsealed" over time vulnerable to rain water getting in. That is why at some gas stations after a hard rain, you fill up and end up having water in your gas. Old mom and pop gas stations are notorious for this if they haven't had new tanks put in recently.

[broken1]

There is an acceptable amount of water that gas stations allow in their tanks because they know it's almost impossible to keep moisture out of things that are buried in the ground, at least thats the case in my neck of the woods.