1974 Johnson 135 HP Outboard Motors Service manual, Page 14Get this manual
2-6 TYPE OF GASOLINEUse "Regular" Leaded gasoline or "Premium" Leaded gasoline not less
than 94 Resear ch Method Octane
1 part Lubricant to 50 par ts Gasoline OR: (6 GalTank) pint lubricant to gallons (5 Imperial) of gasoline IMPORTANT: Additive compounds uch as "tWle -up" compounds"tonics,"fri ction reducing" compoWlds, etc, are Wlnecessary and are not ecommendedThe use of OMC engine cleaner, OMC rust preventive oil and OMCFuel Conditioner Is recom mendedAbove 32 FPortable ankPour lubricant into tank, add fuelReplace fille cap securelyTo mix fue l, tip tank on side as hown and back to upri ght positionBuilt-in TankUse large filte CwmeL our lubri cant lowly with the fuel as tank is filledBe low 32 FPortable Tankour approximately one gallon gasoline into tank, add required lubricantReplace fille cap securelyTho oughly mix by shaking tankAdd balance of gasolineBuilt-in ankIn separate containe mix aUlubricant needed with one gallon more of gasOlineUse large filter funn elPour this mixture lowly with fue as tank is fill edPORTABLE TANK BUILT-IN TANK