Inspection Every 1000 Hrs - Yanmar 4JH4-TE Operation Manual

54 5. MAINTENANCE & INSPECTION

5.3.5 Inspection Every 1000 Hrs.

(1) Inspecting Inner Parts of the Seawater Pump
Depending on the use, the inside parts of the seawater pump deteriorate and seawater discharge perfor-
mance drops.
At the specified interval or when the volume of seawater discharged is reduced, inspect the seawater pump in
accordance with the following procedures;
1) Loosen the side cover bolts and remove the side cover.
2) Illuminate the inside of the seawater pump with a flashlight and inspect.
3) If wear plate is damaged, the disassembly and maintenance are necessary.
4) If no damage is found when inspecting the inside of the pump, install a new impeller and reassemble the
side cover fitting the O-ring.
Note:
1. The impeller must be replaced at every 1000 hours even if the impeller is not damaged.
2. When removing the impeller, use the special service tool for removing impeller.
Refer to 5.3.3(5).
If a large amount of water leaks continuously from the water drain pipe beneath the seawater pump during
operation, disassembly and maintenance (replacement of the lip seal) is necessary.
When disassembly and maintenance of the seawater pump is necessary, consult your Yanmar dealer or dis-
tributor.
The seawater pump turns counter-clockwise as viewed from impeller cover side, so the impeller must be
installed as shown in the below figure. If the impeller has been removed for any reason and must be reassem-
bled, be very careful not to make a mistake and turn it in the wrong direction. Additionally, if the engine is
being turned manually, be careful to turn it in the correct direction. Incorrect turning will twist the impeller
blades and damage it.
(2) Inspecting and Adjusting Intake/Exhaust Valve Clearances
When operating for long periods of time, the clearance between the intake/exhaust valve and the rocker arm
will change and affect operation performance. Adjustment is necessary.
Adjustment requires specialized knowledge and techniques. Consult your Yanmar dealer or distributor.
(3) Inspecting and Adjusting the Fuel Injection Spray Condition
Adjustment is necessary to obtain optimal fuel injection to ensure the best possible engine performance. This
inspection requires specialized knowledge and techniques.
Consult your Yanmar dealer or distributor.
(4) Adjusting the Remote Control Cables
Refer to 5.3.1(5).
(5) Inspecting and Adjusting the Fuel Injection Timing
Fuel injection timing must be adjusted periodically to ensure optimal engine performance.
This maintenance requires specialized knowledge.
Consult your Yanmar dealer or distributor.