Bill -- the clearance problem is with the bridge deck ... it's like they force fit the engine in under it. it appears to be at least a inch higher than the 2GM in 505. You'll see it up close this summer ... a marvel of engineering. i had to add antifreeze by poking a small hose in between the cap and the fill ... and the only way you can tell the fluid level is to let it overflow.

OK ... now we know there were two options to get to fresh water cooling. I wonder if they called the version with the Sendure a 2GMF?

specific photos from Rob's nice blog:
http://sailnordicstar.blogspot.com/searc...p;max-results=7

Bob --- if you get over to the west coast give me a buzz as we go out a few times a week, and always like to have visiting j30 skippers sail with us.

thanks everyone for the very helpful information and insight. I was on the boat yesterday and it has a heat exchanger as outlined above. This looks like an after market job as it partially obscures the Yanmar tag id on front of engine. It is brass. The Good,the Bad and the ugly of having one.

Just checked the Sen-Dure website and they do not sell direct. Good news is that the part is approximately $350.

Mark, I had a 2GM20 installed in 2000, when I bought my boat in Mobile and the mechanic said that Yanmar heat exchangers "last forever". Having said that, my boat is in fresh water and not salt (he also made a comment about that also). So I hope your diagnosis was correct, I wouldn't buy one until I took the old one out and had it pressure tested at a radiator shop, like a heater core for your car, should cost about $35 to clean & test.My mechanic went on to say that all other (than Yanmar) engines used inferior hear exchangers and they only lasted a few years. Do you have a cooling problem? I also installed a temp. and oil pressure gauges when the new engine went in.

Steve, I have not had any problems with cooling. This is what I get when I have a mechanic do an engine survey. I have the feeling that they look for any and all issues where they can make a buck. I hate to say that but it does happen. I agree on trying to rehabiliate just like you would for a heater core. Thanks

So OK ... down here getting Vee Jay ready for season, installed new raw water pump because old one was leaking at seals and I didn't have energy to rebuild. But then
NO WATER out exhaust.

Tracked it back to exhaust water injector elbow that I had replaced TWO years ago ... blocked solid with soot mud. not rust, not corrosion. just a black mud. we had a hot summer here and this may have been expanded by some sort of bacteria over the last six months of sitting.

30 seconds with screwdriver to clear out. Hour and a half mechanics around that fix. Fortunately I had my foredeck guy to do the work while I just handed him the tools.

while it looks like there is a hole in the mud ... it was a solid block at least 1.5 inch deep into hole.



{Bill this post probably should be tied in to another thread ... but I couldn't find it.}

Black mud is usually a soft rust product caused by not enough oxygen to form red rust. I don't remember if it is ferrous or ferric.

interesting, this exhaust elbow was put in service April 2008. and today it was solidly blocked. although last May it was working fine during a good 4 hour run ... before lay up for the summer.

It does stay in the water during the summer. Gordon river ... sort of brackish water.

I really think there is some organic thing GROWING in my engine.

Vic - during storage to prevent this in the future you need to flush the engine cooling system with clean fresh water, then put in antifreeze with anti-corrosive properties. I usually disconnect the sea strainer and run a 2 gallon bucket of fresh water through the system with a temporary hose (including the strainer), then transfer the hose to the anti-freeze solution until it starts to come out the exhaust. You then shut down the engine and reconnect the hoses.

When you return to the boat after storage you need to remove and clean or replace (if needed) the engine zincs because the antifreeze leaves a film and coats them.