Should I be worried?

[timothyjohnson40]

1) Performance issue you are trying to correct. WOT 200-400RPM higher than recommended after prop change.
2) Current prop manufacturer, model, aluminum or stainless as a minimum. Solas 4 blade aluminum 17', switched from a factory 3 blade 19'
3) Current prop diameter and pitch (required). 14.5, 17'
4) Wide open throttle RPM and speed with an average load (very helpful). Recommended 4400-4800, now getting 5000-5200. Average speed at WOT 38-40MPH
5) Engine/drive make, model, year, and HP. Mercruiser Alpha 1, 135HP
6) Boat make model, year, length and weight. 2008 Sea Ray 175 Sport, 2100 dry weight average load is 600-700lb's

Achieved goal of better hole shot and it yanks me out of the hole on a slalom but I am mildly concerned about the higher RPM's. We rarely if ever run at WOT. We normally cruise at about 25-28MPH and RPM hold steady at 3500. Thoughts?

Im a newbie boat owner so go easy

 

[BigDfromTN]

Re: Should I be worried?

1)
Achieved goal of better hole shot and it yanks me out of the hole on a slalom but I am mildly concerned about the higher RPM's. We rarely if ever run at WOT. We normally cruise at about 25-28MPH and RPM hold steady at 3500. Thoughts?

Im a newbie boat owner so go easy

Based on your comment of "Achieved Goal"...

My thoughts are that prop selection is always a compromise and trade off. If this one is doing good at what you do most of the time then keep it. I would not suggest to let engine over rev. Just make sure you let any other drivers know to back off the throttle when not towing and running at WOT.

 

[steelespike]

Re: Should I be worried?

The prop calculator says 5200 rpm 2.0 ratio, 17" prop 12% slip = 36.8.
Maybe you can refine your numbers a little more carefully maybe the speedo is a little high.
As has been said if it does it for you stick with it just be sure all know about rpm.
A same prop in a 19" should knock off about 300 to 400 rpm give you a little more speed and still have good hole shot.
As a side note the 4 blade should stay on plane easier at reduced throttle, seem smoother and respond better around the dock.

 

[jestor68]

Re: Should I be worried?

Just don't push the throttle handle all the way to the stop and you won't over speed the motor.

That's what the rest of us do when running our "ski prop".

 

[timothyjohnson40]

Re: Should I be worried?

Thanks for the replies guys. I'll double check the numbers this weekend but sounds like I'll be fine.