I happen to be doing some research and came across Mercs recommendation for fuel and some cautions. Since the boating season is about to start and fuels are being mixed I was wondering what adverse effects the new mixture might have on our engines. Note this is straight from Mercs site.
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What type of fuel can I use? Model
Gasoline (Notes 2&3)
Additives
1987 and Newer: V8 350 cid, Except EFI Models. (Note 1)
1990 and Newer: 4 Cyl 181 cid, V8 454, & 502 cid, Except EFI Models. (Note 1)
1991 and Newer: V8 540 & 572 cid, Except Supercharged Models. (Note 1)
US/CAN - 87 (R+M)/2 98 RON minimum octane major brand of unleaded regular or premium without alcohol
NON US/CAN - 90 RON minimum octane major brand of unleaded regular or premium without alcohol (Note 4)
None Required
EFI: V8 350,454 & 502 cid. (Notes 1 & 5)
US/CAN - 87 (R+M)/2 minimum octane unleaded regular or premium without alcohol, DO NOT USE Leaded Gasoline
NON US/CAN - 90 RON minimum octane major brand of unleaded regular or premium without alcohol(Note 4)
None Required
V6 and All Other Older 4, 6 Cyl & V8 Models, Except Supercharged Models.
US/CAN - 87 (R+M)/2 minimum octane unleaded regular or premium without alcohol, DO NOT USE Leaded Gasoline
NON US/CAN - 90 RON minimum octane major brand of unleaded regular or premium without alcohol (Note 4)
A good-grade automotive valve lubricant
Black Scorpion models
S/N 0L005600 and below - DO NOT USE Leaded Gasoline
US/CAN - 91 (R+M)/2 minimum octane unleaded regular or premium without alcohol
NON US/CAN - 98 RON minimum octane major brand of unleaded regular or premium without alcohol
S/N 0L005601 and above - DO NOT USE Leaded Gasoline
US/CAN - 87 (R+M)/2 minimum octane unleaded regular or premium without alcohol
NON US/CAN - 90 RON minimum octane major brand of unleaded regular or premium without alcohol
None Required
Supercharged Models
US/CAN - 92 (R+M)/2 minimum octane Unleaded premium without alcohol, DO NOT USE Leaded Gasoline
NON US/CAN - 98 RON minimum octane Unleaded premium without alcohol (Note 4)
None Required
Notes:
The cylinder heads on these engines have hardened exhaust valve seat inserts.
If gasoline with alcohol must be used, periodically inspect complete fuel system for leaks and do not store fuel in boat's fuel tank for long periods of time.
To increase valve life on all MerCruiser engines, the following recommendations should be considered:
Use a propeller that allows engine to operate at or near the top of its maximum RPM range when at full throttle with a normal boat load.
Operation at 3/4 throttle setting or lower is recommended. Refrain from prolonged operation at maximum (full throttle) RPM.
If unleaded gasoline is not available, use a major brand of leaded gasoline.
MCM 5.7L Alpha or Bravo EFI: S/N 0F415136 and Below
MCM/MIE 454 & 502 Magnum Stern Drive or Ski EFI: S/N 0F417515 and Below
MIE 350 Magnum Ski EFI: S/N 0F350545 and Below.
USE 87 (R+M)/2 or 90 RON minimum octane Unleaded REGULAR Gasoline Without Alcohol. DO NOT USE Premium Gasoline.
Can I use reformulated or oxygenated fuels? Reformulated (oxygenated) gasolines are required in certain areas of the USA. The two types of "oxygenates" used in these fuels are alcohol (ethanol) or ether (MTBE or ETBE). These reformulated gasolines are acceptable for use in your MerCruiser engine.
If the gasoline in your area contains either methanol (methyl alcohol) or ethanol, you should be aware of certain adverse effects that can occur. ++++++++++++++++++++++++++++++++++++++++++++++
Guess we all need to be a little concerned about life expectantcy of our engines with the new formulations containing ethanol.
Mike -
