1978 Johnson 55 HP Outboards Service Manual, Page 32Get this manual
CLEANING, INSPECTION AND REPAIR aThe fuel pump operating components are not serviced separatelyIf malfunction occurs, replace the complete pumpFor Fuel Pump Pressure Test, see Page 3-16bInspect the filter for accumulation of sediment by removing the filter cap screw and the filter capSee Figure 3-27cClean all parts of the filter assembly and fuel connectors in solvent and blow dryDO NOT dry parts with cloth, as lint may stick to the parts and clog the passages or prevent the fuel pump valves from seatingDissolve any gummy deposits with OMC Accessory Engine Cleaner (certain solvents will not dissolve these deposits)
Figure 3-28Fuel Tank Upper Housing
It is recommended that new gasket be in-
DESCRIPTION The fuel tank is of simple but rugged construction, with capacity of gallons (22.7 litres) of fuel mixtureIt includes the bulb primer (for priming the fuel pump), fuel level gage, fuel hose and connectors, bracket arrangement to hold the fuel line when not in use, and carrying gripThe fuel tank upper housing, which provides the connection to the fuel hose, contains two release valves and disc valve which prevent any escape of gaSOline or fumes