Yamaha F50F Service Manual page 294

TRBL
SHTG
Fuel system
Check the fuel pump dia-
phragm.
Cracks or damage?
No
Check the vapor separator nee-
dle valve.
Is the needle valve
bent or worn?
No
Check the resistance of each
injector and check the injectors
for clogs.
Good condition?
Yes
Check the ignition system.
9-21
Troubleshooting
Yes
Replace the diaphragm.
Yes
Replace the needle valve.
No
Replace the injectors.
6C13G11