1991 Johnson/Evinrude EI 60 thru 70 outboards Service Manual, Page 24Get this manual
Fuel Requirements
Minimum Octane Models 60, 65WMLEI 70 65RS, WMLK, WMLY Recommendation See fuel classifications belowSee fuel classifications below
PCE0020
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 alcohol by volume:
ETHANOL METHANOL with cosolvents
The use of premium grade fuels is specifically encouragedMost national brand premium fuels contain detergent and dispersant ingredients advertised to reduce intake valve and fuel injector depositsThese ingredients also remove and prevent carbon buildup on pistons and ringsThese ingredients can extend engine life while maintaining high level of performanceUnacceptable Fuel: Do 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, regardless of octane rating