PERIODIC MAINTENANCE
Every 1000 Hours of Operation
Perform the following maintenance every
1000 hours or 4 years of operation,
whichever comes first.
• Checking the Fuel Injection Timing
• Checking the Fuel Injector Spray
Pattern
• Replacing the Seawater Pump
Impeller
• Cleaning and Checking the Seawater
Passages
• Checking Diaphragm Assembly
(3JH4E / 4JH4AE only)
• Replacing the Alternator V-Belt
• Adjusting Intake / Exhaust Valve
Clearance
• Checking the Remote Control Cable
Operation
• Adjusting the Propeller Shaft
Alignment
Checking the Fuel Injection Timing
See your authorized Yanmar marine dealer
or distributor.
Checking the Fuel Injector Spray
Pattern
See your authorized Yanmar marine dealer
or distributor.
Replacing the Seawater Pump
Impeller
The seawater impeller must be replaced
every 1000 hours even if it is not damaged.
See Checking or Replacing Seawater Pump
Impeller on page 69.
74
Clean and Check the Seawater
Passages
After prolonged use, clean the seawater
passages to remove trash, scale, rust and
other contaminants that collect in the
cooling water passages. This can cause
declining cooling performance. The
following items need to be inspected:
• Heat Exchanger
• Pressure Cap
See your authorized Yanmar marine dealer
or distributor.
Check Diaphragm Assembly
(3JH4E / 4JH4AE only)
NOTICE: If the diaphragm is damaged,
crankcase pressure control is affected.
Excessive crankcase pressure will cause
leaks at seals and mating part surfaces.
(2)
(3)
(4)
(9)
(8)
(7)
Figure 28
1 – Diaphragm Cover
2 – Spring
3 – Center Plate
4 – Diaphragm
5 – Rocker Arm Cover
6 – Breather Baffle
7 – Baffle Plate
8 – Intake Silencer
9 – Breather Pipe
See your authorized Yanmar marine dealer
or distributor.
JH4 Series Operation Manual
(1)
(5)
(6)
0003628
Need help?
Do you have a question about the 3JH4E and is the answer not in the manual?
Questions and answers
Have to keep filling water in heat exchanger .Pls help
@Alan whitley