Shouldn't have panicked

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Sep 7, 2004
23
Hunter 33 Marina Del Rey, CA
Went out yesterday (6/11/05)on my 2004 H33 w/Yanmar 29hp, before leaving the slip I always check the fluids, Raw Water Strainer, etc.. Started motoring out around 2700 RPMs in 8 - 12 knot winds, passed the 5 Knot limit and cranked it up to 3200 RPMs, within 2 minutes the Overheat alarm lit-up and buzzed. I panicked and didn’t know what to do, so I: Dropped the engine into neutral, raised the mainsail and began sailing around the very busy channel. Went below to call SEA TOW and noticed that the alarm stopped. I didn't see any smoke or smell anything. I put the engine in forward, revved up to 2400 RPMs and then made my way back to the slip. When I docked, I noticed that the Anti-freeze went from pink to a rust color. I forgot to check the Strainer to see if anything was in it. I'm wondering what I should have done when the Alarm sounded: Drop Anchor ? If so, where should I ? Call Sea Tow ? Put the engine into Reverse to blow out ? Someone mentioned it, but not to sure what would happen, or what that would do ? I had the engine serviced and all fluids replaced and sailed the previous weekend without overheating and running the engine between 2800 -3600 RPMS for over an hour. Any advice or proper protocol would be helpful.
 
G

Gary Wyngarden

Overheating

Alan, About six years ago my engine overheated twice on successive weekends and I ended up being towed back in. One of those times, my father in law was on board taking lots of pictures of us being towed in by Vessel Assist. This experience strengthened my resolve to get better educated about my engine and how to deal with problems. In your situation I would continue to sail the boat with the engine off until I got out of traffic. With another helmsperson on board, I'd have them sail the boat while I investigated the problem. If by myself I'd either heave to with plenty of room or find a quiet place to anchor while I investigated. First thing to check is cooling water. Is the through hull open for the raw water intake? Check the raw water strainer and clear it of any blockages. If that doesn't solve the problem, try removing the hose from the seacock to see if any water comes in. If no, then try to shove a coat hanger through to clear any blockages. You might have to check the raw water pump to see if the impeller got destroyed by running it without water. If so, replace it. If you don't know how, have someone teach you. It's easy and will give you more confidence out on the water and save expensive repair bills. It's also my opinion that 3200 rpms is a might hard to be pushing your engine. Hope this helps. Gary Wyngarden S/V Wanderlust H37.5
 
Feb 15, 2004
735
Hunter 37.5 Balt/Annapolis/New Bern
Also, unless I'm really missing something...

putting the engine in reverse isn't going to do anything different for the engine(i.e., not blow it out.) Gears only change the direction of turn in the transmission.
 
Jun 21, 2004
129
- - Westbrook, CT
Happens to me all the time...

.. when I forget to open the raw water seacock! However, since it sounds like you do a careful "pre-flight" inspection, that was obviously not your problem. No, reversing the engine doesn't work. The cooling water still goes in the same direction. When that alarm goes off, here are some possible causes: 1. You forgot to open the seacock (well, that's what usually happens to me). 2. The raw water impeller has gone to the big marina in the sky. Change it every off-season, and keep a spare anyway. 3. Some seaweed or other marine junk has found its way into your raw water intake and is stopping things up. Once you got the sails up, I would have shut down the engine just to stop the sucking. There's a good chance that whatever was clogging the raw water system was stuck right at the intake, and that would have given it a chance to float off. It sounds like you did pretty well getting the sails up and keeping steerage. I doesn't sound to me at all like you panicked. If the problem hadn't fixed itself, I think you would have had to consider dropping the anchor to give you time to sort it out, do that stuff Gary suggested, etc. The only other thing I would have done differently is that I would have gone sailing after the alarm stopped! Paul sv Escape Artist h336
 

AndyK

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Mar 10, 2004
195
Hunter 33 Salem, MA
I agree...

Has happened to me a couple of times with my 3ym30 on my 2004 H33. First time was when I tried running the engine at 3400 RPM (with a 3 blade prop) to out run an oncoming lightning storm. The second time was a clogged raw water strainer. I would get the sails up if they were down and drop the engine to neutral to see if I could cool the engine gracefully. If the strainer is only partially clogged the engine should cool enough so you don't have to shut it down too hot. Both times I have been able to successfully cool the engine to clear the alarm.
 
Sep 7, 2004
23
Hunter 33 Marina Del Rey, CA
Thanks...

First, thanks to all who responded. Am I running my engine to high ? My dealer, who commissioned the boat, said that 3600 is max. cruising on the 3YM30. I cruise around 2800 RPMS most of time, but have been told to run at around 3400 RPMs everytime I'm out for no more than 10 - 15 minutes, and then once I dock I let the engine run in Neutral to cool down.
 
Dec 2, 2003
4,245
- - Seabeck WA
On my H34 the biggest contributor to overheating

was the Perko strainer. Hunter builds these boats with an open through-hull. That has let Puget Sound seaweed in, that has even gotten past the strainer and reached the raw water pump. Still haven't figured out that one. Anyhow the cure is to install a screened through-hull or a filter basket over the outside of the existing through-hull. Both methods are 'haul-out' jobs.
 
Dec 10, 2003
158
Hunter 30_88-94 Edmonds, WA
Touch the mixing elbow

This really sounds like a raw water intake clog---even though you checked it, the most likely time to suck something in is while idling at the dock, or while motoring out at low speed. I'm not familiar with this particular engine, (I have a smaller Yanmar), but locate the mixing elbow. It should always be cool enough to touch, even after running for more than an hour. If it is very hot, you have a cooling water clog somewhere, or a failed impeller. Cruising RPM for Yanmar is 80% of max RPM. You can run it higher for up to an hour, keeps the mixing elbow nice and clean
 
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