If you ride a carbureted scooter (or motorcycle) and are getting your fuel from “ordinary” fuel pumps, you are almost certainly getting an ethanol blended fuel that is NOT good for your machine. Ethanol (ethyl alcohol) has several chemical properties and effects which render it to be incompatible with several conventional engine parts. There are four main areas of concern caused by ethanol blends:
Solvent – Ethanol will dissolve plastic, rubber, fiberglass and even aluminum. Ethanol can dissolve and disintegrate just about anything that has accumulated in a motor. For example, ethanol will dissolve resins that create a black sludge that coats and travels through an engine causing engine stalling and complications including clogged fuel filters and carburetor jets.
Water – Ethanol will absorb water. It combines with water and the combined molecules are greater than the sum of each separate molecule. Petroleum and most other oil-based compounds are not soluble in water.
Temperature – Ethanol ignites at a higher temperature than the gasoline it is blended with and can cause damage to engine pistons.
Shelf Life – Ethanol has a short shelf life, only about 2 – 3 months in ideal conditions. It begins to separate from the gasoline it was blended with very quickly.
Your carbureted, air-cooled scooter will be much happier with Non-Oxygenated fuel (pure gasoline).
Fuel injected scooters have fuel pumps and move fuel at much greater pressure than gravity/vacuum systems. As such, they are more tolerant of ethanol blends. As for myself, I run Non-Ox fuel in all my two-wheelers, carbureted or fuelies. There are several sources to locate Non-Ox (ethanol-free) fuel in your area. One of my favourites is Pure-Gas.org for lists by state throughout the USA.
Currently, the blended fuel being forced upon us is 5% or 10% Ethanol. There is a big push by the EPA to ram 15% Ethanol down our throats even though it is NOT approved for use in scooters or motorcycles by their manufacturers and will void warranty coverage. I strongly recommend that you stick with Non-Ox fuel, especially in your carbureted scooter.
More About Scooters & Ethanol Blends
The Scooter Madness Blog has a posting from Erik Baeumlisberger about the potential problems that fuel blended with ethanol can cause in a lot of scooters, particularly the air-cooled and carbureted scooters so commonly seen on the road in the USA. CLICK HERE or on the image to jump to the blog entry.