On Sun, 25 Nov 2007 17:49:19 -0800, Stephen Trapani
wrote:

Bruce in Bangkok wrote:
On Sun, 25 Nov 2007 08:11:30 -0800, Stephen Trapani
wrote:

Bruce in Bangkok wrote:
On Sat, 24 Nov 2007 23:49:00 -0500, Wayne.B
wrote:

On Sat, 24 Nov 2007 22:12:41 -0600, Brian Whatcott
wrote:

snipped
The Perkins I have in the sail boat has a continuous rating of 3,000
RPM and for years I ran it at 1500 - 1800. When I overhauled it I
could see no evidence of abnormal wear or carbon or any other evidence
that slow running harmed anything.

I have the feeling that someone once said "it's not a good idea to
idle a diesel for a long time" and as the message passed from dockie
to dockie it became an urban legend and now everyone is worried about
idling the engine.
The issue with my motor, the Yanmar 2QM15, is that it runs cold at low
RPM. I can verify this. It's amazing how long it stays cold with no
load. This would be bad for it, right?

Stephen

If your engine runs cold put a thermostat in it. Your Yanmar should
warm up like any engine and stay the same temperature from then on.
Running an engine at a lower then designed temperature is not the way
to go.

Why didn't Yanmar put a thermostat in this engine? Is there any
disadvantage to having the thermostat?

Stephen

Well, I think that they did. At least the 2GM20 I owned had a
thermostat and the parts book shows two, a normal temperature one for
freshwater cooling and a low temperature one for salt water cooling.


Bruce-in-Bangkok
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from address for reply)