Yamaha- Boston Whaler Prop Performance Help

[John from Madison CT]

Greetings Guys,<br /><br />Here is the story:<br /><br />Boat: 22' Boston Whaler Outrage ('88) with Whaler Drive Bracket/Tee Top and Front Curtain Installed.(only giving the facts I think are relevant to performance). ~50gal Fuel, 2 Avg. Size guys. (Light load overall, IMO)<br /><br />Motor: '97 Yamaha 250hp EFI.<br /><br />When I test drove the boat, it would max out RPM's at 4900. When trimmed out further, it would start to porpoise at 5000RPM's.<br /><br />WOT Speed was ~43-44MPH.<br /><br />Prop: Looks like Yamaha 14 7/8" x 21" Pitch. I believe this is the Saltwater Series Yammie Prop..<br /><br />I would guess that this boat is over propped. I realize that the Max RPM's for this motor are spec'd at 4500-5500RPM's with Max HP at 5000RPM's.<br /><br />What would you guys do, drop down to a 19" Pitch, probably gain 400RPM's? Any Speed Gain/Hole Shot? There is a 15 1/4" Diam. x 19" Yammie of the same series available.<br /><br />Any particular Prop brand recommendations?<br /><br />Any advice is welcome.<br /><br />Thanks,<br /><br />John from Madison, CT

 

[JB]

Re: Yamaha- Boston Whaler Prop Performance Help

Hi, John.<br /><br />I would definitely drop to a 19". I might try a cupped 19" SS. <br /><br />Good luck.

 

[DP]

Re: Yamaha- Boston Whaler Prop Performance Help

Dropping down to a 19 pitch will give you more bang on the hole shot but probably drop your top end mph a bit.<br />Stick with a Yamaha prop or a Mercuty hubed for the Yamaha. I thing the Merc props out of the box are better than any others.

 

[John from Madison CT]

Re: Yamaha- Boston Whaler Prop Performance Help

Thanks guys....now to find a used 19" Yamaha prop....or better yet..trade my 21" Yamaha prop for a 19".<br /><br />Appreciate the help.<br /><br />John