Yamaha F100B F100C Outboards Factory Service Manual, Page 78Get this manual
Fuel system
NOTE: Make sure that air does not escape from the opposite side of the fuel pump To eliminate any gaps between the fuel pump valves and the fuel pump body 2, and to ensure better seal, make sure that the inside of the fuel pump is moist with gasolineFuel pump pressure a: 50 kPa (0.5 kgfcm2, 7.1 psi) Fuel pump negative pressure b: 30 kPa (0.3 kgfcm2, 4.3 psi)
Checking the fuel pump