1985 OMC 65, 100 and 155 HP Models Commercial Service Manual, PN 507450-D, Page 96Get this manual
Fuel System Trouble Isolation Chart Problem: Engine Malfunction Due To Fuel System Step 1Check Fuel Supply Is there fuel in tankIs the fueloil mixture correct? Is the fuel fresh? Is the fuel tank clean inside? Is there water in the fuel? Is pickup screen blocked? Result Fuel OKGo to step 2Fuel questionableDrain and fill tank with correct mixtureFuel tank dirtyClean fuel tankStep 2Check Fuel Filter Remove filter cover and inspect screen varnishInspect gasket See Inline Filter InstructionsResult Filter screen cleanGo to step 3Screen dirtyClean or replaceGasket OKGo to step 3Not OKReplaceStep 3Check Fuel Delivery Disconnect fuel hose at motorHold outlet end of primer bulb up and squeeze primer bulb until definite pressure is feltInspect for leakageConnect fuel hose to motorHold up and squeeze primer bulb until definite pressure is feltInspect for leakage from hoses, fuel pump, filter and carburetor