Yamaha F90D Service Manual page 226

TRBL
SHTG
Symptom: Engine does not accelerate when the throttle is opened quickly.
The engine turns off when the throttle is opened quickly.
Acceleration is tardy and the engine is likely to stop at any moment.
• Check the engine using the diagnostic flash indicator or the Yamaha Diagnostic System.
Symptom: Engine can run, but engine speed will not increase.
Overheat warning indicator is on.
Oil pressure warning indicator is on.
Warning indicator is on and buzzer is sounding.
• Check the cooling system.
• Check the lubrication system.
Cooling system
Check the cooling water inlet for
clogs or debris.
Clogs or debris?
Yes
Clean the cooling water inlet.
Check the thermostat operation.
Good condition?
Yes
Check the cooling water tem-
perature sensor.
Good condition?
Yes
Check the engine using the
Yamaha Diagnostic System.
9-11
Troubleshooting
Check that cooling water is
No
discharged from the cooling
water pilot hole.
No
Replace the thermostat.
No
Replace the cooling water tem-
perature sensor.
Is water
discharged?
Yes
Check the water
passage.
No
Check the water
pump impeller.
Yes
Good condition?
No
Replace the
impeller.
6D81G11