1985 OMC 65, 100 and 155 HP Models Commercial Service Manual, PN 507450-D, Page 102Get this manual
Built-In Fuel Tank System Check
Built-in fuel systems MUST be checked for restrictions as part of normal motor installation.1
When permanent installed fuel tanks are used, some anti-siphon valves, primers, filters, etcmay present restrictions greater than can be tolerated by the engine fuel pumpsToo great restriction could reduce fuel flow to the engine resulting in poor performance and possible engine damageC01849
Fuel Pump Suction Test
1To perform this test to measure the ability of the built-in fuel system to deliver fuel to the engine's fuel pumps, use OMC Special Tool PIN 390954 (fuel line vacuum tester)2Start and run engine before installing vacuum testerShut engine off after operating temperature is reached3Disconnect fuel line from engineConnect fuel line vacuum tester between engine and built-in fuel lineDo not squeeze bulb after vacuum tester is installed as this will damage gaugeIt is important that the fuel line vacuum tester be properly main tainedAll hose connections and pipe threads must be air tightAny air leaks introduced at this point will make accurate fuel system troubleshooting difficult