2004 SR Johnson 2-stroke 40, 50HP Service Manual, Page 158Get this manual
FUEL SYSTEM PRIMER PUMP
PRIMER PUMP
40R, 40RL MODELS
Remove primer plunger from housingDiscard rings
Disassembly
IMPORTANT: To prevent excessive fuel spillage, disconnect hose connector at outboard before disassemblyLoosen screw retaining the primer pump knob shaft and disconnect the knob from the pumpRemove primer pump mounting screws, disconnect fuel hoses, and remove pump29283
IMPORTANT: The three smaller O-rings are made with special material; use only the proper O-rings
Cleaning and Inspection
Inspect brass plunger shaft for any burrs or scratchesRemove small scratches by polishing the plunger with crocus clothIf the plunger has deep scratches, replace the plungerInspect plunger where cross hole intersects inside holeAny burrs around cross hole will accelerate wear of O-ringsRemove any protruding burrs and polish with crocus cloth