2-36
BF135A•BF150A
Clean the water screen.
• Check the water pump and
replace if necessary.
• Check the water tube for
blockage and deformation.
Replace if necessary.
YES
Start the engine and check the
water check port with the engine
idling.
Does the cooling water flow
through the water check port
continuously?
NO
YES
NO
NO
NO
YES
The system is restored to nor-
mal operation.
Perform ECT sensor 2, 3, and 4
troubleshooting (P. 5-51, 52, and
55 or 5-84. 86, and 89).
Replace the thermostat.
Stop the engine and check the
water screen.
Is the water screen clogged?
NO
YES
Put the outboard motor into gear
and let the engine idle for a few
minutes to cool it down.
Do the overheat indicator light
go OFF and the warning buzzer
stop sounding?
Check the thermostat.
Is the thermostat normal?