Fuel Requirements; Fuel Ratings; Using Reformulated (Oxygenated) Gasoline (Usa Only); Gasoline Containing Alcohol - Mercury 350 Scorpion ECT MerCruiser Operation & Maintenance Manual

Table of Contents

Advertisement

Section 4 - Specifications

Fuel Requirements

Running out of fuel can damage catalyst components. Do not allow the fuel tanks to become empty during operation.
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 will not be covered under the limited warranty.

Fuel Ratings

Mercury MerCruiser engines will operate satisfactorily with any major brand of unleaded gasoline that meets the following
specifications:
USA and Canada ‑ 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 ‑ 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) Gasoline (USA Only)

Reformulated gasoline is required in certain areas of the USA and are acceptable for use in your Mercury MerCruiser engine.
The two types of oxygenates used in these fuels are alcohol (ethanol) and ether (MTBE or ETBE). If ethanol is the oxygenate
that is used in the gasoline in your area, refer to Gasoline Containing Alcohol.

Gasoline Containing Alcohol

If the gasoline in your area contains either methanol (methyl alcohol) or ethanol (ethyl alcohol), be aware of possible adverse
effects. These adverse effects are more severe with methanol and worsen according to the percentage of alcohol in the fuel.
Alcohol in gasoline can absorb moisture from the air, causing the water and the alcohol to separate from the gasoline in the fuel
tank.
IMPORTANT: The fuel system components on your Mercury MerCruiser engine will withstand up to 10% alcohol content in the
gasoline. We do not know what percentage your boat's fuel system will withstand. Contact your boat manufacturer for specific
recommendations on your boat's fuel system components (fuel tanks, fuel lines, and fittings).
Be aware that gasoline containing alcohol may cause increased:
Corrosion of metal parts
Deterioration of rubber or plastic parts
Fuel permeation through rubber fuel lines
Starting and operating difficulties
Fuel leakage is a fire or explosion hazard, which can cause serious injury or death. Periodically inspect all fuel system
components for leaks, softening, hardening, swelling, or corrosion, particularly after storage. Any sign of leakage or
deterioration requires replacement before further engine operation.
IMPORTANT: If you use gasoline that contains or might contain alcohol, you must increase the frequency of inspection for
leaks and abnormalities.
IMPORTANT: When operating a Mercury MerCruiser engine on gasoline containing alcohol, storage of gasoline in the fuel tank
for long periods should be avoided. Long periods of storage, common to boats, create unique problems. In cars alcohol‑blend
fuels normally are consumed before they can absorb enough moisture to cause trouble, but boats often sit idle long enough for
phase separation to take place. In addition, internal corrosion may take place during storage if alcohol has washed protective
oil films from internal components.

Engine Oil

For optimum engine performance and maximum protection, use the following oil:
Application
All MerCruiser engines
IMPORTANT: Lubrication requirements for catalyzed engines differ from the requirements for noncatalyzed engines. Some
marine‑grade lubricants contain high levels of phosphorus. Although these high‑phosphorus lubricants may allow acceptable
engine performance, exposure over time will damage the catalyst. Catalysts damaged by lubricants containing high levels of
phosphorus may not be covered by the MerCruiser Limited Warranty.
Page 42
Recommended Oil
Mercury/Quicksilver 25W‑40 Synthetic Blend Engine Oil, NMMA FC‑W Catalyst Compatible rated
NOTICE
WARNING
!
90-8M0099729
NOVEMBER 2014
eng

Advertisement

Table of Contents
loading

Table of Contents