Right Prop for Yamaha 115 4 Stroke

fireblast2591

Recruit
Joined
Nov 18, 2009
Messages
1
I have a 2005 Sea Swirl 19.5 Ft. Boat with a Yamaha 115 4 Stroke on it. The boat is very slow planning out with 4 people and only tops out at 38 mph @ 4900 rpm. It does not throw a rooster tail but spays out the sides. What prop should I use for better planning and speed ?
 

jevery

Chief Petty Officer
Joined
Jun 16, 2006
Messages
538
Re: Right Prop for Yamaha 115 4 Stroke

We need to know what prop's on it now to help. This 18-1/2 ft is hitting 6000 RPM and 37 MPH with a 17P prop. You definitely need to get your max RPM up at least close to 6K with a drop in pitch. I doubt you'll get more top speed, but you'll sure improve holeshot and planing speed. A 115 seems a tad small for a 19-1/2 footer.
 

BaileysBoat

Senior Chief Petty Officer
Joined
Sep 29, 2008
Messages
716
Re: Right Prop for Yamaha 115 4 Stroke

Motor is a little small.

Your tach can't be reading right.
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: Right Prop for Yamaha 115 4 Stroke

Welcome,
Considering the size of the boat your speed is pretty good.Is it by GPS?
I to wonder about your tach/rpm and prop size.Size usually appears under the prop nut or on the barrel.
 
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