Can water get up to the air intake??

[Kettlewell]

There could be a plugged anti-siphon valve in a loop that should be in your water intake line that goes into the exhaust elbow to cool it. If that line is below the water line on your boat there is a potential for a siphon to set up that can fill your waterlift muffler and then back up into the engine. You can read more about that here.

[Mattyb]

Actually funny you mention that. There is a hose that comes off the exaust part that has been blocked and doesnt go anywhere ( done by previous owner) There were never any issues so never really thought more of it. More investigation needed.

Also, Because I fried my starter motor I have just rung around for a new one, $1200!!!! Couldnt beleive it. How would someone go about finding an aftermarket starter for an old Yanmar? I have the part number.

[Kettlewell]

Get the starter rebuilt. I would guess that any automotive/truck starter place could do it. Are you sure it is fried? It could just be stopped cold because that engine won't turn over.

[Mattyb]

Nah, think it is stuffed because I can still turn the engine by hand. Well I can get it to TDC and cant turn past that but it would have been able to move a bit.

First Auto elec wouldnt even look at it, Said it would cost more for him just to take it apart. I live in a remote mining town so everything costs a fortune here ( Labour is $170 an hour)
I found a local Mechanic who said its been a while but he will have a look at it. Fingers crossed.

[Kettlewell]

With the cost of a new starter it might be worth it shipping it to someplace willing to rebuild it. The fact that the engine turns is a good sign. You should be able to get to those cylinders either by taking the head off or pulling the injectors, then you can suck the water out with a vacuum and run some clean oil down there a few times to flush moisture out. If you have the starter working or you can crank by hand you can turn it over to expel any water. Have to do this soon in order to avoid getting a lot of rust in there. After you get it running I would do a couple of oil and filter changes after just an hour or so of running not under load, just to get all the moisture out.

Not sure why the PO would block the vent line off allowing the water to potentially siphon. Anyone who has fooled around trying to get a plain hose to siphon liquid knows that it sometimes takes quite a few tries to get it going--it isn't an automatic thing. So evidently you have been lucky until now when something aligned all the stars just right and a siphon started up.

[Mattyb]

yep I think you have hit the nail on the head. You would be amazed what the PO has done. Almost had a fire due to all the exposed electrical wiring Behind the engine, Half the controls are held together with ducktape and leaks plugged with plumbers tape. Am slowly getting through it all one by one! I tell ya patience is the key when it comes to yachts :-) Have had her for about 8 months now but Just love it and although there is a lot to fix she has always go me home even when one of the diesel pressure lines burst going in to the top of the injectors and diesel was spraying out everywhere she still motored another half an hour to get me to the mooring!

Thanks for everyones help. Unless something weird happens now hopefully I can remedy with all the suggestions here.

[chris_gee]

I wonder if you have a fine crack in your exhaust elbow. That can send a fine spray of salt water onto your air filter, engine mounts, and lead to the fuel lines rusting through..

[Neo]

We bought a boat with a 2gm20 about 8 months ago also. If you need the shop manual send me a PM and I'll send you the pdf file.

[Mattyb]

Chris the Exhasut elbow is on the other side of the engine so I think I am pretty right there. The diesel line breaking was due to the engine mounts having no rubber left in them and it basically work hardened one of the lines going to the filter.

NEO That would be awesome. PM Sent. I do love the little engine so want to give it as much TLC as it needs.

[foggysail]

Originally Posted by Kettlewell

With the cost of a new starter it might be worth it shipping it to someplace willing to rebuild it. The fact that the engine turns is a good sign. You should be able to get to those cylinders either by taking the head off or pulling the injectors, then you can suck the water out with a vacuum and run some clean oil down there a few times to flush moisture out. If you have the starter working or you can crank by hand you can turn it over to expel any water. Have to do this

Kettlewell--NO! He said above that the engine will not go beyond what he calls top dead center. Sure, he may need to rebuild the starter...maybe but he is risking his engine trying to force it to turn.

I agree with you about maybe having to pull the head off. Years ago a friend had problems with a 20HP or so Yanmar. His instruction from Mack Boring was to loosen the injector clamps, NOT REMOVE THEM, crank the engine and the compression then pops the injector. Cannot do that in this case because the engine will not make a complete revolution. By the way, Mack Boring stressed it was important to keep the injector holding bracket on the injector but loose of course. They warned the safety issues without the holding bracket, the injectors will launch themselves with enough force that if it hit someone in the head it could kill them.

I think the OP is screwed, my guess is he will have to pull the head. And teh longer he waits, the more damage that will occur if that water is raw sea water. JMHO

Back to the starter-- the chances favor that his starter has a solenoid. After he resolves his water ingestion problem that would be a good time to try bypassing the solenoid. I really doubt he destroyed the starter but poop still happens.

[Mattyb]

Foggysail you are corrrect and I dont intend to try cranking her until the water issue is sorted. I actually read the link Ketwell has posted and think that is the reason for the water in the first place - Siphoning from the exhaust.

I will see if I can lever the injector out but am thinking pulling the head will be just as easy. Need to read the manuals to see exactly whats involved. The starter is now at a mechanic so hopefully he can suss it out and yes it does have a solenoid so hopefully thats it.

[Mattyb]

oh dear!
Also noticed while having the head off that water was still running out of the cooling holes. Decided bugger it, took the hose off the seacock and yep water running out. Turns out the seaacock doesnt have a stop point and will just turn through, I always assumed that when it hit the wall of the boat it was closed but the closed position is about an inch back! I think this is the actual problem and like what has been said a siphon action was created and with unlimited access to water she simply filled up.

The good news though is once I dried it up and cleaned it up it didnt come up too bad. Have to think of how to clean up the valves though. I dont think all is lost yet. Could definately do with a rebore and I am going to order a gasket kit while I am at it as its fairly shot.

[Kettlewell]

Kettlewell--NO! He said above that the engine will not go beyond what he calls top dead center. Sure, he may need to rebuild the starter...maybe but he is risking his engine trying to force it to turn.

Sounds like he knows enough not to force it--starter was dead, so he was just turning it over with a wrench or something. I was just pointing out that movement was an indication that there wasn't serious damage, which can happen if the waterlock occurs while the engine is running.

Turns out the seaacock doesnt have a stop point and will just turn through, I always assumed that when it hit the wall of the boat it was closed but the closed position is about an inch back!

Need to figure out how to actually close the seacock positively--maybe switch it out for a ball valve that has a positive closure point. But, once you put it all back together you still need to make sure there is a working anti-siphon line running from the top of the loop that injects water into the exhaust. I run mine into a cockpit drain that is near the helm position and I can hear when cooling water is being pumped.

[foggysail]

Originally Posted by Mattyb

The good news though is once I dried it up and cleaned it up it didnt come up too bad. Have to think of how to clean up the valves though. I dont think all is lost yet. Could definately do with a rebore and I am going to order a gasket kit while I am at it as its fairly shot.

First, good to see you pulled the head before real damage could happen. I lost an engine once because a head gasket failed and I was unaware that it did until the following week when I tried to start the engine. It was frozen solid. Even with the engine out, head off so I could soak the pistons with oil I was never able to crank over the engine. My only option was to break the pistons and start the entire process of rebuilding. I swapped the engine out.

I have been down similar roads, things can become ensnaring. There seems to be no end, a little boring here, a valve there, while its apart maybe new rings and before long the entire engine gets torn apart.

If this was my project I would do only those things that had to be done and nothing else. It ran well for you before and it most likely will run well again for you.

[Mattyb]

Thanks foggy sail. I agree, will just tidy her up and a new head gasket.

Kettlewell. I think I know what the problem was and I cant really beleive it.
I am looking into the whole anti siphon thing and looking how everything thing should be set up. I dont have a mixing elbow it seems!
http://www.yanmarhelp.com/images/highrzexh.jpg
in the above picture my exhaust manifold just has a straight small pipe coming out of it and a water pipe goes in to the top of it and that pipe just goes straight to the exhaust pipe which goes to the water lock and straight out. I seem to be missing a mixing elbow. This also pputs the whole set up below the water line! I am actually amazed it took this long to happen.

So much to learn and go over in this boat before I push off! But as my dad just said, Better to find out now than 100's of miles offshore. Plus I am learning a whole heap about diesels!