Yamaha F50F Service Manual page 292

TRBL
SHTG
Out of specification?
No
Check the water pump.
Good condition?
Yes
Check the ignition system, fuel
system, or lubrication system.
Symptom 3: Engine speed not stable at low speeds or hunting occurs.
Check the throttle position sen-
sor and idle speed control and
check that the connectors are
securely connected.
Good condition?
Yes
Check the throttle valve open-
ing.
Is the throttle
valve opening
incorrect or is the
throttle valve link
worn?
No
Check the ignition system or
fuel system.
9-19
Troubleshooting
Yes
Replace the cooling water tem-
perature sensor.
No
Replace the water pump.
No
Repair or replace the defective
parts.
Yes
Replace the throttle body.
6C13G11