Generac Power Systems CT3609 Owner's Manual page 11

IMPORTANT NOTE: It is important to pre-
vent gum deposits from forming in fuel
system parts such as the carburetor, fuel
hose or tank during storage. Alcohol-
blended fuels (called gasohol, ethanol or
methanol) can attract moisture, which
leads to separation and formation of acids
during storage. Acidic gas can damage the
fuel system of an engine while in storage.
To avoid engine problems, the fuel system
should be emptied before storage of 30
days or longer. See the Storage section.
Never use engine or carburetor cleaner
products in the fuel tank as permanent
damage may occur.
Owner's Manual for Portable Generator 9