Yanmar 4JH4-TE. Probably a daft question,

[peterandjeanette]

but does anyone know if these engines use pencil anodes anywhere?

I need to get the engine serviced and on my last boat the engines were festooned with these things.

Many thanks

 

[vyv_cox]

It's an intermediate-cooled engine, so unlikely. There might be one in the heat exchanger, although the GM and YM series don't have any. None mentioned under 'accessories' in the two page description, although I see exhaust elbow and engine mounts are.

 

[Steve Clayton]

Non on mine that I am aware of.

email www.marine-power.co.uk for confirmation

 

[Mistroma]

Pencil Anodes

I have the non-turbo version and asked dealer about this when I had the first service. I was told that there weren't any pencil anodes.

I was also surprised to find that the air filter is just an empty box with no filter. Apparently this is normal as well. You can remove the air filter and look inside to check if yours is the same.

The only parts I change each year are the oil & fuel filters, no air filter.

P.S. Routine servicing is really easy apart from the water pump impeller. I made a removal tool for that and can pass on details if you like. It works very well and cost £1-2 vs. £40 for the pukka Yanmar version.

 

[daveyw]

this manual any good for you?

http://boatdiesel.com/Engines/Yanmar/Yanmar-Manuals.cfm?PDFID=3959300460984

 

[donde]

Mistroma

I would like to know more about the tool for removing the impeller. Removing it has always been the most difficult part of the yearly maintance task.

 

[Mistroma]

Impeller Removal

It is still on the boat so I can't send pictures just now but can describe it and send diagrams later if needed. Very basic tool but works well and is very compact.

The impeller on my Yanmar has a threaded section in the hub and removal is just a matter of screwing the tool into this and then turning a screw to pull the impeller out.

I went to a local shop that sells misc. brass & plumbing items and took my spare impeller. I asked if they had a blanking plug with the same thread. It's a common thread (can't remember what it is).

1) I bought a blanking plug with the correct thread. It just looks like a short solid brass threaded bolt that's hollow.

2) Find a set screw, bolt etc. with a nut that just fits inside the hollow part of the blanking plug. It doesn't need to be too long, about the thickness of the impeller plus the length of the blanking plug. Something around 30-40mm might be OK but I don't have an impeller to hand.

3) Next step is to drill a hole large enough for the screw/bolt thread in the centre of the blanking plug.

4) Wipe a little grease on the threads of the screw/bolt and push it through the above hole. Spin on the nut and tighten it down into the recess in the plug. Push Araldite or similar around the nut to bond it into place inside the plug. You can put a little tape on the protruding threaded section before starting in case you get glue on it.

When it has set you will be able to use it as a puller.

a) Simply unscrew the screw/bolt almost fully
b) Screw the tool into the threaded part of the impeller
c) Turn the screw/bolt and this will pull out the impleller

I hope that this isn't too confusing without pictures.

 

[donde]

Thank you Mistroma!
I am a bit confused but think I will be ok once I get to the boat and can see what you are describing.

 

[Mistroma]

Extractor Diagram

I obtained some Yanmar workshop manuals after I made the puller and thought I'd try to find a picture of the impeller. Didn't need to look at it before now as servicing the pump isn't a problem now.

Guess what, I found a picture of the Yanmar puller I'd seen advertised online at £40 and another puller that's pretty much the same as the one I made up.

I've attached the diagram from the manual and that should make it clearer. I started with a solid threaded plug, drilled a hole and bonded a nut inside the hollow base.

Hope that this explains it. I could draw some more diagrams if needed but try clicking on the diagram below to see more detail. Diagram shows that impeller thread is M18 x 1.5 and you could tap a hole to fit an M10 bolt as shown. I just found it easier to recess a nut in the bottom of my brass plug instead of tapping the hole.

 

[noelex]

The Yanmar impellor puller works well, but only with genuine Yanmar Impellors, which can be difficult to get.. The Jabasco impellors seem identical, but without the central thread.. They come out easily though. The best tool seems to be a multigrip type tool I have, but the jaws are narrow and they can be pushed apart and the jaws are still parallel the pivot point changes.

 

[Talulah]

The Yanmar impellor puller works well, but only with genuine Yanmar Impellors, which can be difficult to get.. The Jabasco impellors seem identical, but without the central thread.. They come out easily though. The best tool seems to be a multigrip type tool I have, but the jaws are narrow and they can be pushed apart and the jaws are still parallel as the changing the pivot point.

I just use snipe nose pliers.
Marine Power sell two different makes of impellor. The genuine Yanmar one @ £36 and the Johnson one @ £30. As stated above the only difference is the central thread to fit the tool.

 

[peterandjeanette]

Fantastic replies.

Thank you, gents. Time to get busy.

 

[eagleswing]

quite useful!

it once took me 4 hours to pull out a yanmar impeller as the jabsco pulller tool would not fit between the pump face and the neighboring bulkhead. only bent-nose needle nose pliers could get in...now i know to use the threaded style impellers. but i had not realized that the threads were different on the yanmar impellers vs. the johnsons..

thanks !