Yamaha F100B F100C Outboards Factory Service Manual, Page 326Get this manual
TRBL SHTG
Troubleshooting
Symptom: Engine can be started, but does not remain on Check the fuel system Check the ignition system Check the compression pressure of the power unit(Fuel system)
Check that the fuel vent screw of the fuel tank is open
Is the vent screw open? Yes Check for water or residue in the fuel filter
Open the fuel vent screw