Thermostat Removal - Yanmar 6LPA-STP2 Service Manual

COOLING SYSTEM

Thermostat Removal

NOTICE: NEVER remove the thermostat. If the
engine is operated with the thermostat removed,
the engine will overheat and could be damaged.
1. Drain the freshwater from the freshwater cooler.
2. Remove the thermostat cover and thermostat.
3. Remove the rubber hose and hose band.
4. Remove the thermostat and the gasket from the
thermostat (Figure 7-9).
Figure 7-9
Figure 7-9
5. Inspect the thermostat for damage. Inspect the
jiggle valve (Figure 7-10, (1)) for damage.
Replace as necessary.
Figure 7-10
( 1 )
Figure 7-10
6. Immerse the thermostat in water and slowly
heat it (Figure 7-11). The valve opening
temperature is indicated on the thermostat.
7-10
7. Check the valve opening temperature. The
valve opening temperature range is 68 to 72°C
(154 to 162°F). If the valve opening
temperature does not satisfy the specification,
replace the thermostat.
Figure 7-11
0005337
8. Check the valve lift (Figure 7-12, (2)). The valve
lift must measure 10 mm (0.393 in.) or more at
90°C (194°F). If the valve lift does not satisfy
the specification, replace the thermostat.
Figure 7-12
0005338
( 1 )
© 2007 Yanmar Marine International
Thermostat Components
0005339
Figure 7-11
Figure 7-12
6LPA Service Manual
( 2 )
0005340