Yamaha F50A Service Manual page 135

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 water cooling system.
• Check the lubricating system.
Check the water inlet for clogs
or debris.
Clogs or
debris?
Yes
Clean the water inlet.
Check the thermostat operation.
Good condi-
tion?
Yes
Check the thermoswitch.
Good condi-
tion?
Yes
Replace the CDI unit.
62Y3A11
Check that cooling water is dis-
No
charged from the pilot water
outlet.
Is water dis-
charged?
Yes
Check the water
passage.
No
Replace the thermostat.
No
Replace the thermoswitch.
Troubleshooting
No
Check the water
pump impeller.
Yes
Good condi-
tion?
No
Replace the impel-
ler.
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