Mercury 25 2-Stroke, Owner'S Manual

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FUEL & OIL
52
Fuel Recommendations
IMPORTANT: Use of improper gasoline can damage your
engine. Engine damage resulting from the use of improper
gasoline is considered misuse of the engine, and damage
caused thereby will not be covered under the limited warranty.
FUEL RATINGS
Mercury Marine engines will operate satisfactorily when using a
major brand of unleaded gasoline meeting the following
specifications:
USA and Canada
‑ having a posted pump Octane Rating of 87 (R
+M)/2 minimum. Premium gasoline (92 [R+M]/2 Octane) is also
acceptable. Do not use leaded gasoline.
Outside USA and Canada
‑ having a posted pump Octane Rating
of 90 RON minimum. Premium gasoline (98 RON) is also
acceptable. If unleaded gasoline is not available, use a major
brand of leaded gasoline.
USING REFORMULATED (OXYGENATED) GASOLINES
(USA ONLY)
This type of gasoline is required in certain areas of the USA. The
2 types of oxygenates used in these fuels are alcohol (ethanol) or
ether (MTBE or ETBE). If ethanol is the oxygenate that is used in
the gasoline in your area, refer to
Gasolines Containing
Alcohol
.
These reformulated gasolines are acceptable for use in your
Mercury Marine engine.
GASOLINES CONTAINING ALCOHOL
If the gasoline in your area contains either methanol (methyl
alcohol) or ethanol (ethyl alcohol), you should be aware of certain
adverse effects that can occur. These adverse effects are more
severe with methanol. Increasing the percentage of alcohol in the
fuel can also worsen these adverse effects.
Some of these adverse effects are caused because the alcohol in
the gasoline can absorb moisture from the air, resulting in a
separation of the water/alcohol from the gasoline in the fuel tank.