[CG Weinert]

Thanks all. 

I’ll shoot for 3425-3525 and not fret about the soot.

Best!

CW

[CG Weinert]

Thanks for the replies Clark and David.

From the conversation I am struggling with what target WOT to use for the propping conversation. Can somebody help – “3100 continuous” or “3300 fuel stop” from the engine plate?

You both mention “high idle,” which brings up an additional question.  I have attached an excerpt from the Yanmar manual which shows high idle at 3750. 

I have been presuming from my web recon, that 3300 + XX is the right WOT target for propping.

Reading Tony’s Tips: I’ve come to translate the terms thus, does the community concur?

·         Continuous RPM – in this case (Yanmar) this is the RPM where the mechanical governor starts to kick in and taper fuel delivery to moderate RPM under load (read Tony’s Tips on continuous duty and Yanmar for more)

·         Fuel Stop RPM – the point at which the engine will no longer allow speed to increase under load, for Yanmar coincides with peak power

·         High Idle – peak, no load RPM

I have also seen that Yanmar propping sheet, as well as hearing from my local Yanmar dealer that “Yanmar likes to prop that engine to 3350”; which may not be quite as conservative as that worksheet.  The worksheet does have a certain vintage look, so I have wondered if the worksheet is ‘old news?’

This local Yanmar recommendation to prop to 3350 , if 3300 is the right baseline WOT, is more or less aligned with the Tony approach of “propping the vessel at full working weight to rated RPM plus 100 to 200 rpm” (http://www.sbmar.com/articles/engine-life-vs-engine-loading/). 

Tony / Corey – if you can make a minute to weigh in, could you be sure to help me understand which number (3100/3300) is the right starting point from your view of the world, please?  (I suspect “3300”).  Also thoughts on how to select max cruise speed (80% of WOT EGT?) would be wonderful while I have your attention.

I certainly want to make sure I am on the conservative side of the line.

Answering David’s other questions:  we see less than 30 seconds of almost-not-there white haze outside the exhaust port at startup, and then never any more.

 

[Author]

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