Thermostat Inspection - Yanmar 3JH4E Service Manual

2. Inspection and adjustment

2.5 Thermostat inspection

(1) Put the thermostat in a beaker with fresh
water, and heat it on an electric stove.
The thermostat is functioning normally if
it starts to open between 75-78 deg C,
and opens until 8 mm or more at 90 deg
C. Replace the thermostat if it not
functioning normally.
Valve opening
temperature
(deg C)*
75.0-78.0
* Valve opening temperature is carved on the flange.
(2) Normally, the thermostat should be
inspected every 500 hours of operation,
but, it should be inspected whenever the
coolant temperature rises abnormally or
white smoke is emitted for a long time
after engine starting.
(3) Replace the thermostat every year or
2000 hours of operation (whichever
comes first).
Full open lift
(temperature)
(mm)
8 or more (90 deg C)
Thermostat cover
Gasket
Thermostat
Gasket
Fresh water
pump body
96
Thermometer
Thermostat
007546-01E
010637-00E