150HP Yamaha on Wellcraft 210 Sportsman

[tdrudd87]

New (to us) boat this spring, and I believe it is slightly over-propped. Gets up and goes just fine, but numbers seem less than perfect.

1) would like to move RPMs into upper half of rev range (4500-5500), based on suggestions for best engine life and performance. Optimize for family cruising with visitors, trolling, and future water sports
2) Current prop is OEM Yamaha Stainless 17-M Saltwater Series
3) Current size 15.25 x 17
4) WOT with 2 adults and full fuel is 5000 @ 40-41 mpg GPS. With 4 adults, 2 kids and dog, 4700 @37-38?mph GPS
5) 2002 Yamaha 150 HP Saltwater Series II (OX66 EFI)
6) 2002 Wellcraft Sportsman 210, 21ft, 3200lb dry weight, approx 4000-4200 for 2 adult #s above?

I've never had a SS prop before and have a bit of sticker shock to try the same Yamaha prop at 15 pitch. Last boat ran a 4 blade Solas Amita that I was happy enough with, but the slip calculations based on the above have me wondering if a 4 blade aluminum would hurt more than help in this case.

Thanks,
Terry

 

[porscheguy]

A lot of people with Yamaha’s like powertech props. I don’t know much about them. 15.25 diameter seems a bit large IMO. Since you’ve got an outboard check the mounting height.

 

[tdrudd87]

Upon further research, the diameter may be off. Definitely stamped on the hub section with 17-M, but I didn't look inside to check the full part number details.

I'll check out the PowerTech props, thanks.

Terry