Yanmar 4JH3-TE, Operation Manual

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5. MAINTENANCE & INSPECTION 45
5.2.5 Inspection Every 1000 Hrs. or 4 yrs.
(1) Replacing the Marine gear Oil and Washing the Lube Oil Filter
(3rd time and thereafter)
Replace the marine gear oil for the 3rd time after 1000 hrs.
At the same time, wash the filter at the marine gear entrance.
→
See 5.2.1(2)
(2) Inspecting Inner Parts of the Seawater Pump
The inside parts of the seawater pump will deteriorate
with use, and discharge performance falls. At the speci-
fied interval or when the volume of seawater discharged
is reduced, inspect the seawater pump in accordance
with the following procedures.
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See 4.9.1(2)
1. Loosen the side cover set bolts (4) and remove the
side cover.
2. Illuminate the inside of the seawater pump with a
flashlight and inspect. If any of the following problems
is found, disassembly and maintenance are neces-
sary.
• Impeller blades are cracked or nicked.
Edges or surfaces of the blades are marred or worn.
The impeller must be replaced periodically every
2000 hrs.
• Wear plate is damaged.
3. If no damage is found when inspecting the inside of
the pump, replace the side cover. Fit the O-ring to the
groove of the joint face before replacing the side
cover.
NOTICE:
• When the impeller has been disassembled, be careful to replace it so that it moves in the
correct direction. The seawater pump turns clockwise, but the impeller blades must be
installed in the counterclookwise direction.
• When turning the engine by hand, be sure to turn it in the correct direction. Turning it in
the opposite direction damages the blades of the impeller.
If water leaks continuously from the seawater pump during operation disassembly and maintenance (replace-
ment of the mechanical seal) are necessary.
When disassembly and maintenance of the seawater pump are necessary, consult your Yanmar
dealer or distributor.
(3) Washing the Cooling Water System and Checking and Maintaining Parts
This maintenance requires specialized knowledge. Consult your Yanmar dealer or distributor.
Over time rust and scale builds up in the seawater and fresh water systems reducing their cooling perfor-
mance. Additionally, when the inside of the engine oil cooler and the marine gear oil cooler become dirty, lube
oil cooling worsens causing the oil to deteriorate more quickly.
Wash the following related parts when the cooling water is being replaced.
Cooling water system related parts:seawater pump, engine oil cooler, marine gear oil cooler, fresh water
pump, fresh water cooler, thermostat, etc.
Seawater pump
Direction of impeller blades
Direction of shaft rotation
KMH4A