Yanmar engine anodes Hunter31

[pateco]

How do other Hunter 31 owners access the engine pencil anodes for replacement?

I have a raw water cooled 2gm in my 1983 H31, and I can't seem to find a tool or method that will let me remove and replace the two anodes. Both are blocked by cabinetry. One by the sink cabinet on the starboard side of the engine bay , and the other by the forward center-line wall of the quarter berth at the aft of the engine bay above the transmission.

In the video below you can see there is an access hatch under the sink, but it is too high to get a wrench onto the anode plug. There is no hatch at the rear of the engine at all.

Have you cut additional access hatches etc.? Is there a trick to this?

I have sat down do do this project 4 times now only to give up after busting a few knuckles.

I am preparing to get out a hole saw, and just cut some new access ports, but I will gladly accept any tips you may have.

https://www.facebook.com/video.php?v=623716974429130

 

[pateco]

OK, so it's been almost 1 day, 26 people have viewed this thread, and no suggestions have been made. Am I the only H31 owner with this issue?

 

[SFS]

Sorry Chip, my 3YM20 is fresh water cooled. I have the same square hole cut in the side of the engine compartment under my galley sink, which I assume was for oil filter access on the original engine. My access to most everything (including the oil filter) is from the shaft side, reaching over the tranny. Don't have enough bandwith to watch the video - where are your zincs located?

 

[pateco]

Sorry Chip, my 3YM20 is fresh water cooled. I have the same square hole cut in the side of the engine compartment under my galley sink, which I assume was for oil filter access on the original engine. My access to most everything (including the oil filter) is from the shaft side, reaching over the tranny. Don't have enough bandwith to watch the video - where are your zincs located?

SFS,

The raw water cooled 2GM has two Zincs

One is on the block between the exhaust manifold and the diesel lift pump.

The other is on the back side of the head above the transmission. (also right up against my aft engine bay bulkhead.

 

[SFS]

Can you get to the one on the sink side through the access panel on the port side of the sink cabinet below the sink itself? If I sit on the galley floor, I have visual access to that side of my engine, while preserving physical access with my left hand through the panel, so I'm not working blind. Bring left-handed would help too, but oh well. If you have better luck than I generally do, the anode is not precisely across from the shelf in that cabinet, so an extension on a socket wrench would allow you to do the work directly under the sink, where there may be more room.

Can't help you on the other side. My engine may be narrower than yours - I do have some working room along the port side, but not a lot.

 

[pateco]

Can you get to the one on the sink side through the access panel on the port side of the sink cabinet below the sink itself?

That is the one I have attempted to do several times. I can get a wrench on it but cannot get a good angle on it or enough torque to move it in the confined space under the cabinet. My next attempt will be to bring my air compressor, and 1/2" impact wrench with an impact wobble extension. Hopefully that will work.

The one at the back of the head however is still screwing with me. I have not thought of a good way to even access it since it is blocked by the bulkhead where my inverter is mounted.

 

[Whatfiero1]

On my H 30. 7 year newer boat I have reworked all my cabinetry to be easily removed to expose complete engine for service and maintenance and every year I check everything and clean engine with tooth brush. Of course my teeth get blackened with old oil after my engine is cleaned.

 

[pateco]

On my H 30. 7 year newer boat I have reworked all my cabinetry to be easily removed to expose complete engine for service and maintenance and every year I check everything and clean engine with tooth brush. Of course my teeth get blackened with old oil after my engine is cleaned.

Any pictures of how you did that? It would make things easier.

 

[Manly]

@pateco, I haven't changed my anodes yet, so I'm afraid I can't help you there.

However, I did make a swinging access panel aft of the engine bay when I was changing out the exhaust hoses. You may find pictures of that helpful.

You mentioned there is an inverter on your wall here. You can see in the picture below I have a fairly bulky Minn-Kota battery charger on the wall too and fortunately the swinging door still worked ok. Here is what it looks like closed:

And here it is open:

Here is the hardware to keep it open:

Also, put a light up in the engine compartment while I was changing things:

This is a pretty crude setup, but it allows me access back there. I had to tack the insulation down around the jigsaw cuts. The hing was a stainless steel piano hinge one of the guys on the dock gave me for free awhile back.

Keep us updated on this anode project, it is on my list too. I have the 2gm20f, so it's a little different than yours, but probably similar.

 

[pateco]

@pateco, I haven't changed my anodes yet, so I'm afraid I can't help you there.

However, I did make a swinging access panel aft of the engine bay when I was changing out the exhaust hoses. You may find pictures of that helpful.

You mentioned there is an inverter on your wall here. You can see in the picture below I have a fairly bulky Minn-Kota battery charger on the wall too and fortunately the swinging door still worked ok. Here is what it looks like closed:
View attachment 147938
And here it is open:
View attachment 147939
Here is the hardware to keep it open:
View attachment 147940
Also, put a light up in the engine compartment while I was changing things:
View attachment 147941
This is a pretty crude setup, but it allows me access back there. I had to tack the insulation down around the jigsaw cuts. The hing was a stainless steel piano hinge one of the guys on the dock gave me for free awhile back.

Keep us updated on this anode project, it is on my list too. I have the 2gm20f, so it's a little different than yours, but probably similar.

That looks like a good solution. I am going to bring the compressor and impact wrench along with a Jig Saw, and see if I can't get this done today.

 

[pateco]

Ok, now I have really messed it up. I went to the boat yesterday determined to get the project completed.

With a short 15/16 socket and a wobble head I still could not get the socket seated on the plug, due to the fuel line being in the way.


So I removed both the fuel line, and the mixing elbow to make room, and was able to get a 6 point socket to fit snugly on the plug.


I had been spraying it with PB Blaster for a while in advance, and I tried using this with my regular socket wrench, and then with a nice breaker bar, but got no movement. So then I made the mistake of breaking out the air powered impact wrench.


It only took a couple of pulses of that wrench to get me to where I am now stuck with a completely rounded off plug.


Now what???? I am stumped. I was planning to try adding heat if the impact hadn't worked, but I was not expecting that plug to round over so easily and I wasn't looking forward to removing all of the rest of the fuel system in advance of that option.

After this debacle, I decided to not even attempt the one on the back of the head until this one is done.

Could it be drilled out? Should I try a 15/16 Bolt extractor?

What would you try next? Please help!!!

 

[Whatfiero1]

Try drilling 3 1/4" holes in zinc to both heat bolt and reduce gripping pressure of that thing then try the extractor or a spanner wrench or pipe wrench

 

[pateco]

So last weekend I brought the map gas torch, and the bolt extractor to the boat, and made several additional attempts to remove the anode plug. I removed the fuel lift pump and fuel lines, as well as the exhaust/mixing elbow to get more clearance for the torch. I found that neither piece had the gaskets they were suppose to have. I then heated the anode plug up until it was smoking hot, and tried to remove with the air impact wrench. The extractor bit worked great, and did not slip on the plug, but I still had no success removing it even with the impact wrench.

I have a race this Sunday, so last night I reinstalled a brand new fuel lift pump along with all new copper washers on the banjo bolts to fix the fuel leak I had going on. I reinstalled the mixing elbow and they both now have the correct gaskets. I re-primed the fuel system, and she is again a runner.

Old leaking fuel pump


New fuel pump partially installed. You can see the Anode plug at the top right of the picture.


I still haven't decided on what steps to take next on replacing the anodes.