1985 OMC 65, 100 and 155 HP Models Commercial Service Manual, PN 507450-D, Page 99Get this manual
Fuel Pump Pressure Test65 Conduct this test on the motor in test tank or on the boatBefore testing, loosen fuel tank gas cap momentarily to release any pressure that may have built upFuel tank must not be more than 61 cm (24") below fuel pump 1Remove carburetor to fuel pump hoseConnect fuel pressure gauge (obtain locally) between the carburetor and fuel pump2Start motor and observe gaugePump pressures should read as belowRPM 600kPa (70 gcm(1 psi) 2500 to 3000 10 kPa (100 gcm 2) (1.5 psi) 4500 17 kPa (170 gcm2) (2.5 psi) 3If fuel pump does not meet these specifications, replace fuel pump