Adjusting The No-Load Maximum Or Minimum Speed; Sensor Inspection; Oil Pressure Switch; Thermo Switch - Yanmar 3JH4E Service Manual

2. Inspection and Adjustment

2.3 Adjusting the no-load maximum or minimum speed

1) After warming the engine up, gradually raise the
speed and set it at the no-load maximum speed.
2) If the no-load maximum speed is out of the
standard, adjust it by turning the high idle limiting
bolt.
3) Then set the no-load minimum speed by adjusting
the low idle limiting bolt.
Standards
No-load maximum
3325±25

2.4 Sensor Inspection

2.4.1 Oil pressure switch

Disconnect the connector from the oil pressure switch.
Keep the voltammeter probes in contact with the switch
terminal and cylinder block while operating the engine.
It is abnormal if circuit is closed.

2.4.2 Thermo switch

Place the thermo switch in a container filled with
antifreeze or oil. Heat it while measuring the fluid
temperature. The switch is normal if the voltammeter
shows continuity when the fluid temperature is 97-103
deg C.
-1 )
(Unit : min
No-load minimum
800±25
38
Remote
control cable
High speed
limiting bolt
Control lever
Cable joint
Oil pressure switch
Tester probes
(Continuity test)
Thermometer
Hot water
Fuel injection pump
Low speed limiting bolt
Cylinder block
(flywheel side)
Tester probes
Thermo switch