1975 Evinrude 40 HP Outboards Service Manual, PN 5093, Page 13Get this manual
ENGINE FUEL AND LUBRICANT RECOMMENDED GASOLINEUse gasoline with the following minimum octane numbersRESEARCH OCTANE NUMBER Most commonly used in the past PUMP POSTED OCTANE NONumber posted on gasoline pumps since September 1973 9l
Below 32 FPortable TankPour apprOximately one gallon gasoline into tank, add required lubricantReplace filler cap securelyThoroughly mix by shaking tankAdd balance of gasoline Built-in TankIn separate container mix all lubricant needed with one gallon or more of gasolineUse large filter funnelPour this mixture slowly with fuel as tank is filled
Lead free or low lead gasoline is preferable, but when not available regular leaded gasoline with these minimum numbers may be used
11riwQ1 NOTE
When operating in any other country than the United States, Canada or Australia, any gasoline may be used which will satisfactorily operate an automotive engineLUBRICANT: Use reputable Outboard 50:1 lubricant which is BIA certified for service TC- (two cycle-water cooled)It is formulated to give best engine performance with least combustion chamber deposits, least piston varnish, maximum spark plug life, and best lubricationSee inside back coverIf