NEW PROPELLER

[Old Screwball]

After a 'mishap' with my last propeller I decided to prop down 1 pitch. New prop is a 14 X 11. I'm running a 2012 75 hp Merc 4 stroke on my 2012 18 foot Sun Tracker Party Barge. There were 2 adults aboard, no wind and no current, Bimini top down. Digital GPS unit said 26.6 mph. That is the best it has been. Tried 15 pitch stainless, 13, and 12 cupped aluminum, and finally the 11 cupped. The cheapo tach says I'm turning 6100 rpm, but the rev limiter isn't cutting in, so I presume it isn't the most accurate tach in the world. I QUIT. No more quest for more speed. Just have to learn that 26.6 is it.

 

[Old Screwball]

OK, here we go again. When I typed this, and previewed it there was a picture of the dash with a digital GPS speedo and my tach. Up until I hit the POST button it was there. I GIVE UP, either I'm doing something wrong, or the site is not operating properly.

 

[PennYanGuy]

I can see the picture.

 

[Old Screwball]

I can too ..... now.

 

[steelespike]

26 sure seems reasonable for a boat that doesn't really plane.
I think if you check the pontoon tests on the Etec sight (they haven the most complete tests)
you'll find that a 18/20' w 40 or 50 had a speed around 18-22 mph
and as you add hp speed only changes up to a point.
If you want to improve speed add a 3rd log and skin the underside.
There is a factory made fiberglass log I forget the name
Videos indicate it planes and handles like a runabout.
Found the name; "pontoon water glide"