PERIODIC MAINTENANCE of Yanmar engine 4JH4-TE 500 and 1 000hours

• 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  

  

 

 Manual for Yanmar 4JH4AE

 

The seawater impeller must be replaced every 1000 hours even if it is not damaged.

 

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.

 

 

 

Cleaning Exhaust / Water Mixing Elbow

The mixing elbow is attached to the turbocharger. The exhaust gas is mixed with seawater in the mixing elbow.

1. Remove the mixing elbow.

2. Clean dirt and scale out of the exhaust and seawater passages.

 

• Replacing Exhaust / Water Mixing Elbow

• Replacing Rubber Hoses Replacing Exhaust / Water Mixing

3. If the mixing elbow is damaged, repair or replace. See your authorized Yanmar marine dealer or distributor.

4. Inspect the gasket and replace if necessary.

Cleaning the Turbocharger (If Equipped)

Contamination of the turbocharger causes revolutions to drop and engine output to fall.

If a significant drop in engine output is noted (10% or more), clean the turbocharger.

This should be done only by a trained and qualified technician. See your authorized Yanmar marine dealer or distributor.

Adjusting the Alternator V-Belt Tension

See Checking and Adjusting the Alternator V-Belt Tension on page 62.

Checking the Wiring Connectors

See your authorized Yanmar marine dealer or distributor.

Tightening All Major Nuts and Bolts

See Tightening Fasteners on page 54 or see your authorized Yanmar marine dealer or distributor.

Elbow Replace the mixing elbow with a new one every 500 hours or 2 years, whichever comes first, even if no damage is found.

See your authorized Yanmar marine dealer or distributor.

Replacing Rubber Hoses

Replace rubber hoses every 2000 hours or 2 years, whichever comes first.