Yamaha F25 Owner's Manual page 27

tions may also result in unscheduled
maintenance, fuel system damage, and
internal engine damage.
Recommended fuel:
Regular unleaded gasoline
Min. pump octane number (PON):
86
ECM01982
NOTICE
Do not use leaded gasoline. Leaded

gasoline can seriously damage the en-
gine.
Avoid getting water and contaminants

in the fuel tank. Contaminated fuel can
cause poor performance or engine
damage. Use only fresh gasoline that
has been stored in clean containers.
Gasoline with Ethanol
Two types of gasoline are commonly avail-
able in the U.S.A. and Canada for use in au-
tomobiles and boats: conventional gasoline
without Ethanol and gasoline with Ethanol,
which is typically referred to as E10 gasoline.
According to federal regulations, E10 gaso-
line may contain up to 10% Ethanol.
A high quality gasoline without Ethanol is the
preferred fuel for your Yamaha outboard mo-
tor. However, if gasoline with Ethanol is the
only fuel available in your area, your Yamaha
outboard motor is calibrated to run properly
on fresh E10 gasoline that meets the mini-
mum octane requirement specified for this
model.
ECM02402
NOTICE
Never use a gasoline for your outboard
motor that contains more than 10% Etha-
nol, such as E15 which contains 15% Eth-
anol or E85 which contains 85% Ethanol,
or gasoline containing any amount of
Specifications and requirements
[ECM04480]
Methanol. These fuels can cause starting
and running problems, as well as serious
fuel system and internal engine damage.
Gasoline containing ethanol has several
properties that may cause boat fuel system
problems.
Ethanol is a strong solvent (cleaning

agent) that can clean gum and varnish de-
posits from a boat's fuel system, particular-
ly in older boats, as well as tanks and pipes
used in gasoline distribution. These re-
leased deposits contaminate the fuel and
can cause problems, such as clogged fuel
filters, carburetors, or fuel injectors, which
could result in engine damage.
Ethanol may dissolve resins used in the

construction of fiberglass fuel tanks. The
dissolved resins contaminate the fuel and
can cause problems, such as clogged fuel
filters, carburetors, or fuel injectors, which
could result in engine damage.
Ethanol is hygroscopic (has a strong at-

traction to water). Therefore, any water
that inadvertently enters the fuel system,
including moisture that is absorbed from
the air, will mix with the ethanol in the gas-
oline. If the amount of water is excessive,
the ethanol and water mixture will separate
from the gasoline in a layer at the bottom
of the fuel tank. This ethanol and water
mixture is very corrosive to aluminum fuel
tanks and fuel system components.
The usable life span of E10 gasoline may

be shorter than the normal length of off-
season boat storage, causing starting and
running problems related to stale fuel.
For more information on using fuel contain-
ing ethanol, visit: http://www.yamaha-mo-
tor.com
Gasoline Filtration
Yamaha outboard motors are equipped with
21