Tom, lots of good suggestions so far. I have one other. When was the last
time your heat exchanger tubes were rodded out? If you are unfamiliar with
this, these are the tubes you see inside when the cap is removed. There should
be a cap on at least 1 end to access the raw water side of the exchanger. If
even some are plugged it will cause overheating. I had about 40% of mine
plugged coming back from Port Townsend. It was an 85* day and no wind (of
coarse) could only motor at 1400 or the alarm would go off. I cleaned mine
using diluted miuratic acid to soften the build up. Then i rinsed it good,
followed bu cleaning the tube with some twisted safety wire in my drill. And a
final wash with the miuratic acid, and another good rinse.
Doug MountjoysvPegasusLF38 just west of Ballard, WA.
------ Original message------From: Tom Buscaglia via CnC-List Date: Sun, May
29, 2016 09:04To: cnc-list@cnc-list.com;Cc: Tom Buscaglia;Subject:Stus-List
Overheating YANMAR
We are on our first extended cruise of the year for a clubevent in Olympia WA
and are hiving a problem with overheating with our3HM35 Yanmar. Here's the
deal...
We usually run as about 26-2800 RPM. Depending on the condition ofthe bottom
and the prop, that gives us between 6.5-7.3 KTS. We havehad some intermittent
issues with overheating, but it was usually mepushing too hard in heavy seas or
running above the usual RPMrange. Backing off always relieved the problem.
And we haveno gauge, so this is all based on the alarm which may or may not
beaccurate.
As we were heading out this time the Admiral was at the helm and I wasbelow
messing with something and the alarm went off as we were running atabout 2200
RPM. We were able to run at under 2000, but above thatthe alarm sounded and we
had to back down. We continued on at 4.5KTS.
I checked the strainer and through hull. All good there. Water seems to be
exiting the exhaust as usual. I am planning on a haulout and bottom job next
month, and did not have a diver clean the bottomand prop (should have done that
for sure). My assumption was thatthe barnacles on the prop and dirty bottom,
along with the 15-20 KT headwind were taxing the engine and causing the
overheating. But the"experts" in my club feel otherwise.
I tried to get at the gooseneck to see if that might be theproblem. I was able
to get the water hose off and poke around inthere with a wire, but decided that
pulling the exhaust hose was notsomething to try 30 miles from home as if I
screwed it up and damages theexhaust hose I could be stuck here for a while.
I have heard all of the problem YANMAR's have with exhaust back up and
amwondering if that may actually be the problem. I have asked tohave it
checked every tine I get the engine serviced, but there's notelling what that
entailed or even if it was done....so, when she goesinto the yard for the pain
job I think replacing the gooseneck with thestainless aftermarket one may be in
order.
Here are my questions:
1. Can the dirty bottomand barnacle encrusted prop- result in an
overheating problem?
2. Would a carboned upgooseneck cause a problem like the one I am
experiencing?
3. Where can I get oneof those nifty aftermarket stainless goosenecks?
Any additional suggestions are welcome and appreciated!
thx
Tom B
.¤º°`°º¤,¸¸,¤º°`°º¤¤º°`°º¤,¸¸,¤º°`°º¤.
Tom & Lynn Buscaglia
SV Alera
C&C 37+/40
Vashon Island WA
(206) 463-9200
www.sv-alera.com
_______________________________________________
This list is supported by the generous donations of our members. If you like
what we do, please help us pay for our costs by donating. All Contributions are
greatly appreciated!
