Boston Whaler 25 Guardian Series, Operation & Maintenance Manual

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3-14
Section 3 Fuel Systems
Blended Fuels
Automotive gasoline has contained various oxygen-
ated hydrocarbon compounds as replacements for
lead since 1985. These compounds boost the octane
rating of gasoline. Two familiar compounds are MTBE
and ethanol. Ethanol is now the most common com-
pound since MTBE was identified as a serious polluter
of ground water.
Ethanol for gasoline is a highly refined grain alcohol
rated at about 200 proof. The U.S. EPA currently
allows automotive gasoline to contain up to 10% etha-
nol, by volume. While E-10 gasoline does not cause
significant problems in road vehicles, it does require
extra attention when used in your boat.
Follow these rules when using E-10 gasoline in
your boat:
• Read and understand all of the fuel-related safety
warnings and maintenance procedures outlined in
this operator manual.
• Read and understand all of the fuel-related safety
warnings and maintenance procedures outlined in
your outboard engine operator’s manual.
• Ethanol is hygroscopic, meaning that it attracts
and easily mixes with moisture. E-10 gasoline will
corrode metal fuel system parts faster than gaso-
line without ethanol. If you are switching to E-10
gasoline, it can loosen scale and deposits in older
fuel systems. Regularly inspect all fuel system
components and fuel filters for signs of corrosion
and particulate contamination.
!
WARNING
The components in your boat fuel system are
designed to work with automotive gasoline
containing up to 10% ethanol, by volume.
Using automotive gasoline with higher
concentrations of ethanol will damage boat fuel
system components and might cause fuel
leaks.