how much speed would i gain

[dpfrost]

I currently have a 135hp merc on a 17' cajun. I have a 19p prop. Running at about 5600 rpm and 54 to 55 mph. How much increase in speed would i gain by going to a 23p. Or would that drop my rpm down to much. Should i go with a cuped 21. And again about how much speed would i gain by it. IF anyone could help me on this i would greatly appriciate it.

 

[LubeDude]

Re: how much speed would i gain

This might better be in the prop section, but here goes. Ever heard of "Hens teeth"?<br /><br />Well, we might be there. Looks like from the #s, you are right at the sweet spot. You didnt say whether you are running a stainless prop, and what make and how many blades. Assuming that you are running a 19P aluminum I would sugest a 17P S/S. If you are running an S/S, you might want to raise your engine a notch and see what happens. A bigger pitch prop right now isnt your answer.

 

[JB]

Re: how much speed would i gain

To Prop Forum.

 

[dpfrost]

Re: how much speed would i gain

3 blade ss 19p quick silver prop.<br /><br />I am just wondering if going up makes a 5 to 7 mph advantage or just 2 to 3.

 

[Dhadley]

Re: how much speed would i gain

As soon as you do it we'll know exactly how that particular 135 reacts on that 17 Cagun with that exact prop.<br /><br />Your gain depends on how much gearcase you're dragging now, what the total weight is in your boat, how that load is balanced, how much (if any) setback you have and what shape the prop is in. Among other things including if the motor is healthy.<br /><br />If its all the way down I'd bet you'll pick up some. Cajuns usually react fairly well.