Haul-out issues

[gamayun]

I replaced the mixing elbow on Kynntana just a little over a week ago. My engine had started to bog down above 1100 RPM. The easy part (~15 minutes) was removing the whole assembly, which consists of 4 bolts to the engine and the hoses on the other side. I took the whole piece to List Marine, an engine repair shop in Sausalito, because they have large wrenches and vices that made it relatively easy, though it still required a lot of muscle to undo the elbow from the assembly. It was completely blocked. My guess is that it's been at least 10 years since replacement, maybe even longer, but I have no history on the boat. It took a little more time to reinstall, maybe an hour, but this included scraping off the old gasket where it attaches to the engine, which was a real PITA. The recommended replacement for the elbows is 5-8 years. Probably dunking in vinegar on a regular basis and running the old soot out before shut down might extend this time. Overall, the time and costs involved seemed like a small price to pay for such an important part of the boat.

[rvivian]

Thanks for the responses.

I went to the local Yanmar engine rep today to buy a new exhaust elbow. (About $200 was his quote.)

But he recommended running the engine and measuring the thermostat housing temperature with an infrared heat gun before ordering the elbow. He said the temperature alarm sensor switch ($38) fails often and perhaps that might be the problem.

So I ordered a $102 set of new engine hoses that "will arrive from Georgia in about 17 days" and headed home.

I'll measure the temperature while returning the boat home and disconnect the temp alarm switch if it is sounding and the temperature is normal. Perhaps the new thermostat will be enough.

I'll look at the elbow (it looks pretty new and shiny) when I change the hoses. I suspect I'll be ordering the elbow at that time.

One never knows, does one.

[rvivian]

Heart's Desire splashed last Friday and we made the return 92 NM trip to her slip on Sunday through Wednesday with a lay day in Kingston, WA where we had a six hour adventure on public transportation involving the ferry and two buses into Seattle and back to buy a raw new water pump because the shaft seal began leaking and the overheating still was not cured. My crew would not agree to let me disassemble anything else for fear we would be disabled and he would not get back to his job. So we limited our motoring speed to keep the temperature at the thermostat around 190 degrees as measured by an infrared temperature gun ($40 well spent).

When we got back to home port I took the hose off the raw water feed to the mixing elbow. The overheating issue was not failure of the high temperature alarm switch as suggested by the Yanmar parts rep, but -- you guys had it right - the 1/2" elbow feeding the raw water into the mixing elbow was completely plugged (although some water still got through).

Next week I think I'll clean the mixing elbow and feed elbow and put it back together and run it for a while to see if more crud accumulates or if the overheating is cured. Maybe the heat exchanger needs servicing too.

Then I'll order and install a new mixing elbow.

Thanks for the help.

[rvivian]

It's a plugged mixing elbow (sigh). Poked around in it and got water flow back, but a lot of black stuff in the water leaving the transom.

Definitely past time for a new mixing elbow. Just have to get the old one off.