1993 Johnson Evinrude "ET" 90 degrees CV Service Manual, P/N 508285, Page 51Get this manual
Fuel Requirements Minimum Octane Models 100WT, WM All Other Models Recommendation See fuel classifications below See fuel classifications below (R+M)2 "AKI" 67 87 "RON" 69 90
Preferred Fuel: Any regular unleaded, regular leaded, or premium unleaded gasoline having the recommended octane rating, and not extended with alcoholAcceptable Fuel: Any of the above gasolines with up to the following percentage alcohol by volume: 10 ETHANOL or METHANOL with cosolvents
fN=J 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 performance
Unacceptable Fuel: Do not use any gasoline having more than 10 ETHANOL or more than METHANOL, even if it contains cosolvents or corrosion inhibitor, regardless of octane rating