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E-10 Gas Problems

In New England E-10 gas is causing multiple problems with small engines. In carburetors it clogs spray nozzles with varnish, ruins rubber tubing, chemically breaks down in 3-4 weeks, clogging filters. Do any preservatives work to prevent this? I’ve had to rebuild carburetors on mowers, riding tractors and marine engines and I’ve seen massive damage to smaller engines. Fellow mechanics are puzzled what to do. Are car engines also susceptible? Any comments or recommendations?

There is a new stabilizer formulated specifically for E10. I think it’s a Sta-bil product. I haven’t had any trouble using E10 in my mower or wood chipper. How old are these small engines that are having problems. Maybe the ethanol is dissolving old deposits that have built up over time.

It’s the ethanol in the gasoline damaging these components. We ran into this same problem when Minnesota first introduced E10 in 1993. Older marine/lawn/small engine fuel systems were never designed to tolerate any concentration of the corrosive nature of ethanol. So after people started complaining about the damage the ethanol was causing to their small engines/classic vehicles, Minnesota decided to allow non-oxgenated (no ethanol) gasoline at some gas stations. So we in Minnesota have the option of purchasing this non-oxgenated gasoline for our small engines and classic vehicles where the fuel systems are not designed to handle the ethanol.

Let this be a warning to those who live in states where E10 is becoming mandatory. Use E10 in your older small engines or classic vehicle, and it’ll damage the fuel system.


run your engine dry…or cut fuel supply and allow the engine to use up gas in carb. use stabilizer and don’t stock up on gasoline months before you need it.

You don’t seem to understand. The problem is not with letting E10 sit in the fuel system. The problem is RUNNING E10 through the fuel system.


I understand…usually there is no problem running small equipment…the problem develops when the ethanol/water phase separates and damages the components. I have been running a generator and snow blower with E10 with no problems…I

How old are these small engines? And do they have plastic gas tanks?


We use E-10 here in Florida, and I haven’t had any of these problems in any of my lawn equipment or carburated motorcycles. Since I go through about a gallon of fuel per year for my lawn equipment, I add fuel stabilizer as soon as I buy the fuel.

Leaving fuel in small equipment for 3-4 weeks has always been a bad idea without fuel stabilizer. Perhaps E-10 is making the problem worse, and the people who should have been using fuel stabilizer all along will finally do it.

Before you ask, my lawn mower has a plastic fuel tank and is 17 years old.

Here’s where we can get non-oxy fuel for our small engines/classic vehicles in Minnesota.


Google “gasoline with ethanol” and get news reports effects of ethanol on several types of materials, including the boat fiberglass gas tanks.
On small engines, you’ll need to find a source of seals, gaskets, etc., which are immune to the effects of ethanol. Ethanol additive isn’t going away. Get prepared.

Marine engine Sta-Bil will get you away from those problems.