Honda BF8, BF9.9 and BF10 Outboard Motors Shop Manual., Page 181Get this manual
bINSPECTION THERMOSTAT
1) Immerse the thermostat in water as shown2) Heat the water and observe the operation of the thermostat as the water temperature increase
3) Measure the water temperature when the thermostat starts openingDon't let the thermometer and thermostat touch the container; this may cause false reading4) Measure the lift height when fully open
Start opening
1 Lift height
THERMO SENSOR
60 (140F 70 (158OF) More than 3.0 (0.12in)1
2P CONNECTOR
THERMO SENSOR
The sensor resistance decreases as the coolant temperature increases as shown in the right chart
1) Disconnect the 2P connector from the thermo sensor and