[C320-list] Cooling system

[Doug Treff]

Rich,

I didn't do this myself - I had a mechanic do it because I had additional concerns about what damage had been done to the engine when the elbow clogged. But based on some info that I just found online, it appears that the junction piece between the Exhaust elbow and the mixing elbow is right hand on one end and left hand on the other end. Theoretically enabling you to unscrew it in place to get the elbow off. One of the forum posters states that the threads in the mixing elbow are left-hand and the threads in the exhaust elbow are right-hand. The junction I refer to is pictured in the article here. And the parts are labeled. Don't mix up the terminology between the "exhaust" elbow and the "mixing" elbow. Two different parts.
http://www.cruisersforum.com/forums/f54/removing-yanmar-3ym20-mixing-elbow-127983.html

However, easy removal is seldom the case with these things if they were assembled without anti-seize compound, especially if they've been assembled for a long time. The best advice is to remove the entire assembly by removing the 4 bolts and taking the exhaust elbow off the engine. 

Then you can put the assembly in a vise and use large pipe wrenches to "encourage" it to turn. Failing that, maybe a torch will help loosen things up. There just isn't room in the engine bay and the engine moves around in the mounts when you tug on the exhaust.

Obviously, when you reattach the manifold to the engine, you will want to clean the mating surfaces and install a new manifold gasket as well to avoid exhaust leaks.

Hope this helps,

--
Doug Treff
doug at treff.us

On Fri, Oct 12, 2018, at 1:14 PM, islgirl3 at aol.com wrote:
> I understand that one side of the exhaust assemble is left hand thread 
> and the other right?
> Rich Nuzzolo Barbara RitaHull 897
>  
>  
>  
> -----Original Message-----
> From: Doug Treff <doug at treff.us>
> To: c320-list <c320-list at lists.catalina320.com>
> Sent: Thu, Oct 11, 2018 4:47 pm
> Subject: Re: [C320-list] Cooling system
> 
> Makes sense. Fix it now before your engine dies of a heart attack. 
> Because that's what happens if you let it go. If the elbow clogs, then 
> hot gases melt your exhaust hose. The water has to go somewhere and it 
> could drain down the exhaust manifold and if it gets in the cylinders, 
> you will have a very expensive repair job.
> 
> It happened to me and I had a cabin sole covered in exhaust water. The 
> mechanic told me I was very lucky the engine wasn't damaged by 
> waterlock. The cleanup was still expensive but way cheaper than a new 
> engine.
> 
> How strong is the water flow out your exhaust? It should be pretty 
> strong especially at higher RPMS. After I installed the new elbow, I 
> noticed a dramatic increase in water flow which tells me it had been 
> restricted for a while.
> 
> 
> --
> Doug Treff
> doug at treff.us
> 
> On Thu, Oct 11, 2018, at 8:56 AM, William Russell wrote:
> > I've been noticing what appears to be steam coming from the exhaust
> > discharge lately.  Asked the Yanmar rep at the Annapolis boat show, who
> > said I should replace the exhaust elbow, and do the hose to the Aqualift
> > muffler box at the same time.  Does that make sense to y'all?
> > Where's the best place to buy those parts?  Reading previous posts, I'm
> > assuming this is a job I can do myself.
> > Bill Russell
> > "LIttle Wing," 1998 C320 #545
> > Ithaca, NY