1974 Johnson 135 HP Outboard Motors Service manual, Page 30Get this manual
CLEANINGINSPE CTION AND REPAIR
aThe fuel pump operating conlponents are not serviced separatelyIT malfWlction occurs, replace the complete pump after testing fuel pump as described belowbInspect the filte for accumulation of sediment by removing the filter cap scr ew and the filter capSee Figure 3-22SCREEN
c Clean aU parts of the filter assembly and fuel connectors in solvent and blow dry00 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 Cleane (certain solvents will not dissolve these deposits) NaTE It is recommended that new gasket be Installed when servicing
the fuel pump assembly
TESTING FUEL PUMP
Conduct this tes on the motor In test tank or on the boat1Connect fuel pressure gauge between the carburetor and fuel pump
as illustrated in Figure 3-23O NaTE
Before testing, loosen fuel tank gas cap momentarily to release any pressure that may have built upFigure 3-22
PUMP UNDER TEST