Thermostat Inspection - Yanmar 3JH4E Service Manual

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 8mm 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
inspected every 500 hours or operation, but,
it should be inspected before this if the
cooling 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).
Thermometer
Thermostat
Full open lift
(Temperature)
8 or more (90deg C)
thermostat should
Thermostat cover
Gasket
Thermostat
Gasket
Fresh water
pump body
(mm)
be
39
2. Inspection and Adjustment