Ethanol in Gasoline

[JHAQ]

Are any readers knowledgeable about effect of ethanol in gas on small carburetted engines -- even after non use for a few weeks ? I have a small motor scooter ( 249 cc ) & if such gas is present have great trouble starting it due to EtOH hygroscopicity & gum formation . Small engine dealers ( scooters , boat outboards , generators ,etc ) dont seem to want to admit this problem until it is too late . Is it not a pending disaster for sales of such engines ?

[Rev Blair]

It shouldn't be a problem, but there are a few things that might come up.

 

The first is that many small engines use a mixture of plastic and rubber parts in their fuel systems. some of those materials dissolve when exposed to alcohol. Make sure that all parts in the fuel system are compatible with ethanol use.

 

The next is small 2-stroke engines. These are the ones that use a fuel/oil mixture instead of having a separate lubrication system. They gum up if you leave fuel in them whether that fuel is ethanol or gasoline.

 

Third would be evaporation. E-10 is 10% ethanol, E-85 is 85% ethanol. Ethanol evaporates faster than gasoline, so that mixture will change if left to sit in an open system. Many small engines, like those on yard equipment, have a carburetor and a vented gas cap, so the system is open. They also don't have computer-controlled fuel and ignition systems, so can be tuned only to one kind of fuel.

 

As somebody who still drives trucks with carbs instead of fuel injection, I can tell you that evaporation is a problem now even with conventional gasoline. I have no data, but I think the fuel makers are doing less to inhibit evaporation since it isn't an issue in fuel injected (closed system) vehicles.

 

If you aren't using an engine or the fuel that powers it regularly, I suggest getting a fuel stabilizer suitable for your fuel type. If you can't find it at your regular auto parts store, try a speed shop that caters to the hot rodders and racers.