Yanmar 4JH5E Impeller replacement

Nov 11, 2011
2
In the Mood 393 Toronto
My Yanmar Series 4JH5E Engine has reached 900 operating hours. I feel it is overdue for a sea water impeller replacement. Having reviewed the manual and looked at the engine, it appears that this vintage of engine (2002-03) does not have an easily accessible impeller housing.

Does anyone have experience maintaining this type of engine? What little I have found on line suggests, that I will require exactly the right tools, a great deal of time and patience to do this myself. Any recommendations would be welcomed.
 

Rick I

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Jan 6, 2007
414
CS36Merlin and Beneteau 393 - Toronto
If yours is a 4JH5E the impeller is right at the font and easy to get at not like my 4JH3E where you have to be a contortionist and remove the alternator and water pump to easily get at the impeller. But if it's an 02/03 it's probably not a 5E.

4JH5E



4JH3E This pic looks like it's from a 2004 B393.

 
Sep 25, 2008
7,290
Alden 50 Sarasota, Florida
Can't help with the access issue but wanted to congratulate you for having an impeller which lasted 900 hours. That must be a world's record! Can I borrow your rabbit's foot?
 
Jun 9, 2004
615
Catalina 385 Marquette. Mi
Can't help with the access issue but wanted to congratulate you for having an impeller which lasted 900 hours. That must be a world's record! Can I borrow your rabbit's foot?
Nice snide remark. Actually some of us know better....but in my Yanmar 3jh5e manual, the manufacturer recommends replacement after 1000 hrs. I say again...1000 hrs.


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 (3JH5E / 4JH5E Only) •Replacing the Alternator V-Belt •Adjusting Intake / Exhaust Valve Clearance •Checking the Remote Control Cable Operation •Adjusting the Propeller Shaft Alignm
 

Rick I

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Jan 6, 2007
414
CS36Merlin and Beneteau 393 - Toronto
Actually my impeller on the 4JH3E lasted over 2000 hours. It was so difficult to replace I left it in till I got a slight leak in the water pump. When I finally took it out it was missing one vane which I found in the oil cooler.
 
Dec 2, 1999
15,184
Hunter Vision-36 Rio Vista, CA.
If you can cut an access panel on the port side of the engine it will make the process tollerable. We did this on our Hv36 3jh2e.
 

Rick I

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Jan 6, 2007
414
CS36Merlin and Beneteau 393 - Toronto
If you can cut an access panel on the port side of the engine it will make the process tollerable. We did this on our Hv36 3jh2e.
Unfortunately the fridge is right there.