Inspection Every 50 Hrs. (Or Monthly) - Yanmar 3YM20 Operation Manual

4. MAINTENANCE AND INSPECTION
(7) Adjusting the Tension of Alternator
Driving Belt
When there is not enough tension in
the V-belt, it will slip and the fresh wa-
ter pump will fail to supply cooling wa-
ter. Engine over-heating and seizure
will result.
A Push
When there is too much tension in the
V-belt, the belt will become damaged
more quickly and the bearing of the
fresh water pump may be damaged.
1. Check the tension of the V-belt by
pressing down on the middle of the
belt with your finger (approx.
98N(10kgf)). With proper tension, the
V-belt should deflect 8-10 mm
(0.315-0.393 inches).
2. 2.If the V-belt deflection is out of the
limit, adjust the V-belt tension. Loosen
the set bolt and move the alternator to
adjust the V-belt tension.
3. Be careful not to get any oil on the V-
belt. Oil on the belt causes slipping
and stretching. Replace the belt if it is
marred.
A
4.3.2 Inspection Every 50 Hrs. (or
Monthly)
(1) Drain the fuel/water separator.
1. Close the fuel cock of a fuel tank.
2. Loosen the retaining ring and remove
the filter cup. Drain off any water and
dirt collected inside.
3. After reassembly, be sure to vent air
from the fuel system.
If air is in the fuel system, fuel cannot
reach the fuel injection pump.
Vent the air in the system according to
the following procedures.
(Fuel filter)
A Air bleeding bolt D Filter element
B Bracket E Filter cap
C O-ring F Retaining ring
Fuel system air bleeding procedures
A
EN
B
C
D
E
F
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