2003 Johnson ST 55 HP WRL 2 Stroke Commercial Service Manual, PN 5005483, Page 106Get this manual
FUEL SYSTEM FUEL FILTERS STEP 4 With hose removed from small nipple on top side of primer pump, operate primer pumpFuel should squirt from small nippleResults: If primer fails to pump fuel, inspect primer nipple for obstructionsClean fitting with Cleaning Tool, PIN 326623, and retest If primer fails to pump fuel, disconnect inlet hose from the larger nipple on the primer pumpIf fuel does not flow freely from hose, there may be problem with the carburetor inletRefer to CARBURETOR Cleaning and Inspection If the primer pump has fuel available and is still not working, or the pump is leaking externally, replace the a-ringsRefer to PRIMER PUMP
FUEL FILTERS
Service fuel filter or filter element during 10-HOUR INSPECTION (refer to MAINTENANCE section), and annually or every 100 hours thereafterUnscrew in-line filter coverIt is not necessary to remove fuel hoses to service filterInspect filter and replace as needed