1968 Evinrude Speedifour, Starflite 85HP Service Manual, Page 27Get this manual
mixturePetroleum gum and varnish which precipitate stale mixture clog the filter screen and any small orifices, interferringwith starting and normal runningFor mixture, see Owner's Manual CLEANING, INSPECTION, AND REPAIR
UPPER HOUSING AND FUEL LEVEL INDICATOR The fuel level indicator is mounted to the housing and fuel line assemblyThe entire assembly removed removing the attaching screwsLift the assembly from the tank carefully to avoid damaging the indicator float the screen at the end of the lineSee Figure 3-30
assure that the fuel tank contains the mixture, drain and flush the tank at least once and at every tune-up major repaircomplete draining the tank, drain screw is vided in the tank housingSee Figure 3-29Clean the tank flushing with clear gasoline solventSee Manual for correct mixture