Evinrude E-tec 75 HP, Service Manual

Page: 193 / 344

193
COOLING SYSTEM
ENGINE TEMPERATURE CHECK
9
ENGINE TEMPERATURE
CHECK
IMPORTANT:
The engine temperatures listed
below are based on an intake water temperature
of 70° ± 10°F (21° ± 3°C).
Install correct test propeller and place outboard in
a test tank or in the water. Start outboard and run
at 3000 RPM in FORWARD gear for at least five
minutes. Remember, running outboards at high
speeds in test tanks may disrupt water flow to
gearcase water intakes. Make sure the outboard
has adequate water flow.
Reduce outboard speed and run engine at IDLE
for five minutes. Check IDLE operating tempera-
ture.
Increase speed to 5000 RPM and check tempera-
ture.
If engine temperatures are not within range, trou-
bleshoot cooling system.
If engine temperature tests within range, but the
SystemCheck
gauge indicates a “WATER TEMP”
warning, refer to WATER TEMP/ HOT Circuit
Test on p. 133.
Software Method
Use the
Evinrude
Diagnostics Software program
to monitor engine temperature.
Typical temperature sensor readings at IDLE
speed should be 155°F ± 5°F (68.3°C ± 3°C).
Typical temperature sensor readings at WOT
speed should be 160°F ± 40°F (71°C ± 22°C).
At 5000 RPM, operating temperature must not
exceed 212°F (100°C).
Pyrometer Method
Use a Temperature Gun, P/N 772018, or a digital
pyrometer to measure the outboard’s operating
temperatures.
Measure temperature of the thermostat housing at
the top of cylinder head.
Typical pyrometer readings at IDLE speed should
be 145°F ± 10°F (63°C ± 6°C).
Typical pyrometer readings at WOT speed should
be 150°F ± 40°F (66°C ± 22°C).
CAUTION
When servicing the propeller, always shift
the outboard to NEUTRAL, turn the key
switch OFF, and disconnect the battery
cables at the battery.
Engine Monitor Screen 006307