1988 Johnson Evinrude CC 60 thru 75 outboards Service Manual, Page 82Get this manual
Fuel Recommendations Fuel Requirements
Models 60-75 65 RS; WMLT, WMYT
Recommendation See Fuel Classifications Below See Fuel Classifications Below
Minimum Octane Pump Posted 87 67
Preferred Fuel: Any regular unleaded, regular leaded, or premium unleaded gasoline having the recommended octane rating and not extended with alcohol is the preferred fuelAcceptable Fuel: Any of the above gasolines with up to 10 maximum alcohol volume10 ETHANOL (ethyl alcohol) (may be called gasohol) METHANOL (methyl alcohol) +5 cosolvent alcohols Unacceptable FuelDo not use any regular unleaded, regular leaded or premium unleaded gasoline having more than 10 ETHANOL or more than METHANOL even if it contains cosolvents or corrosion inhibitor and regardless of octane ratingINotel Alcohol extended fuels may result in engine running quality problems, vapor lock or "fuel starvation" problems, or moisture absorption (phase separation) problemsIf running quality problems are experienced, switch to gasoline without alcohol as described in Preferred FuelOMC products have been designed to operate using the Preferred Fuel or Acceptable Fuel; however, be aware of the followingaThe boat fuel system may be different regarding use of alcohol fuelsRefer to boat owner's manualbAlcohol attracts and holds moisture which may cause corrosion of metallic parts of the fuel systemcMetallic and nonmetallic parts of the entire fuel system should be inspected frequently and replaced if signs of excessive stiffness, deterioration, corrosion, or fuel leakage are foundInspect at least annuallyFuel leakage can contribute to fire or explosion-