Yamaha F25C Service Manual page 178

TRBL
SHTG
Within specification?
Yes
Disassemble the carburetor and
check the internal parts for
clogs, debris, or wear.
Clogs, debris,
or wear?
No
Check the ignition system or
lubrication system.
9-5
Troubleshooting
No
Adjust the pilot screw.
Yes
Clean or replace the defective
parts.
6D55F11