1997+ Mercury 35/40HP 2 Cylinder Outboards Service Manual PN 90-826148R2, Page 140Get this manual
Testing Install cle ar fuel hose(s) betwe en fuel pump and carburetor(s)Run engine, and inspect hose(s) for air bubblesIf air bubbles are found, se "Air Bubbles in uel LineIf air bubbles are found, se "Lack of uel Pump Pressure "PROBLEM: AIR BUBBLES IN FUEL LINE Possible Cause Low fuel in tankCorrective Action Fill tank
PROBLEM: LACK OF FUEL PUMP PRESSURE Possible Cause Anti-siphon valveCorrective Action efer to "C hecking for estricted uel Flow aused by Anti-siphon Valvespreceding"Air Bubbles in Line,precedingF uel
Air in fuel line
Dirty or clogged fuel fil- Cle an or replace filterterDirty or clogged fuel Cle an or replace pickuppickup in fuel tankWorn out fuel pump dia- ebuild pumpphragmD efective check valves ebuild pumpin fuel pumpBroken check valve re- ebuild pumptainerPulse hole pluggedHole in pulse hoseLoose pulse hoseR emove pump cle an out holeTighten connectionand