Would you accept this RPM at WOT?

[Aqualift]

I have a 1970 Glastron V-142 SkiFlite with a 1965 Merc 500. I hit approx 5000 RPM at WOT. The prop is 10 3/4" and 11 pitch. The motor should be between 5200 and 5600 RPM's. I'm running the boat in waters over 7300 feet above sea level. This makes my old motor more like 40HP. I figure the total weight is near 900 lbs with all my gear.(trolling motor, two group 29 batteries, fishing tackle, anchor, fuel, etc.) Top speed is around 29 MPH. To get it into the RPM range, I would have to go as low as a 9 pitch prop. That would slow the boat down even more. Should I just accept 5000 RPM's with one person and as low as 4800 RPMs with more people?

Video of it in action here.

http://www.youtube.com/watch?v=YFtUaNj-SEM

 

[CanWoodsman]

Re: Would you accept this RPM at WOT?

Dropping to a 10" or 9" would increase your RPM up into the proper range and should not effect your top speed very much(less pitch but higher RPM). Your older motor will last longer also. If your usually alone go with the 10" & if you usually have company go with the 9". Your 11" will be a great spare.

 

[hwsiii]

Re: Would you accept this RPM at WOT?

A 10" pitch will bring you to right at 5,500 RPM, and that would be perfect for your setup, especially when you have more people than just you and the acceleration will be much better at all RPM.


H

 

[Aqualift]

Re: Would you accept this RPM at WOT?

Thanks for the input. Now I need to find a 11 spline 10 3/4" 10 pitch prop. Those 11 spline props are hard to come by.