On Fri, 29 Apr 2005 19:26:16 -0400, Hans wrote:

Hi,

I hope some people can help me out here.

I have a Pursuit 24 (aprox. 5000 lbs.) walkabout with 2 x 115 HP
Yamaha 4 cycle outboards.
3500 RPM show about 18 kts (GPS).

I am just wondering what a good cruising engine speed would be for
decent engine life. I have heard everything from 3500 to 6000!

Here's my opinion which has worked very well for me with my boats
which have all been outboards.

Bring the boat slowly up until you are planing. There should be a
jump in rpm as soon as the boat is trimmed out and planing properly.

That's where your boat is going to be the most efficient. Bring it up
another 300 RPM or so and that should be a very nice cruise speed.

There is a viewpoint that says WOT is the most efficient, but I can't
seem to make that connection with my outboards. With mine, 2/3 of the
available RPM is both the most efficient and the most comfortable.

Later,

Tom