Help buying a new prop for my Triton

[daveb990]

I want to buy a new three blade prop for my 1999 TR-19 with a 1999 mercury 175 EFI. Right now it has a four blade 24 pitch trophy plus on it with all the plugs out of it.
With my wife and me and all our gear and a half tank of gas or more we get on pad in about three seconds and have a top speed of 60 to 62 mph. I have had it
up to 63 but I was running 5900 rpm and could trim up more and run higher rpm but I don't want to run the motor to many rpms so I backed off some. I usually
run 5600 to 5700 rpms at around 60 mph. I no nothing about props or what I should buy like pitch and diameter and where to buy. Some help would be greatly appreciate.

[SeaPro Admin]

Sounds to me like you need a little more pitch. Here's a starting point: https://www.mercurymarine.com/en/us/...tor/#/step-one

[daveb990]

I went to the link and did the formula and the website said I need a Tempest Plus three blade 14.625 diameter and 27 or 26 pitch RH prop or a 14 diameter fury 27 or 26 pitch.

[daveb990]

I would also like to add that I took my friend fishing the other day that is not a fisherman and he is a big boy. I don't know what he weighs but it has got to be over 400 pounds. With him
me and my wife all our gear and half tank of gas we got on plane in 10 seconds and had a top speed of 58-59 mph with my current prop.

[SeaPro Admin]

You're numbers aren't too bad with your current prop and that link just provides a good starting point based on the factors you put in it. It could take some tweaking from their recommended prop but ideally, you want your best performance at WOT and at the factory recommended max rpm which I believe is 5800 for the 175 EFI. Based on the numbers you posted, you can exceed the recommended max rpm so it sounds like your current prop is under pitched a bit and you need more pitch to drop the max rpm. Their suggestion of a 26 or 27 sounds about right but as I said, it could take some tweaking from there.

[daveb990]

So would it hurt the motor at all to go out and hammer down and see what max rpms that I can run ? I usually either let up on the gas a little or trim down a little to keep it
at 5700 rpms

[SeaPro Admin]

So would it hurt the motor at all to go out and hammer down and see what max rpms that I can run ? I usually either let up on the gas a little or trim down a little to keep it
at 5700 rpms

Backing down to 5700 is playing it safe by keeping it under the recommended 5800 but since it will turn over 5900 at WOT, it's not running at optimum performance and you'll get better mpg and mph if it's propped to keep it at or close to 5800 trimmed out at WOT. You can open it up as a test but I wouldn't run it more than a couple hundred rpm over the 5800 for very long.
Each inch in pitch equates to about 200 rpms, so since you're running a 25 now and the calculator suggests a 26 or 27, I suspect you won't turn more than 5900 or 6000 rpms with your current set up. If I were you I'd find a prop shop that will let you test a prop to be sure it's in the right range.

[daveb990]

I have maybe one boat shop about an hour away that I can talk to and see if they will work with me. So I have a four blade 24 pitch, when going from a four blade to a three blade do you go up or down in pitch ?

[Savage]

Your 175 will never turn a 26P or 27P Fury at the proper WOT rpm. Forget the Mercury prop charts, they can steer you in the wrong direction.

When you trim up with your current prop, is the GPS speed continuing to climb, or are the RPM'S just increasing? What is your PTP? What is your water pressure @ WOT?

[mdtritn21]

How much set back and what do you want more speed or to keep your hole shot? Hole shot get the 24" prop repaired to get rid of the slip and for speed get a 25" trophy with an 8" jack plate with either one. Forget a 26" or 27" prop

[daveb990]

I would like a little more speed. I don't know the prop to pad but the motor is bolted onto the pro Hi jacker second hole from the top and the jack plate is set at 2" high if that helps. I'm not sure how much set back a pro hi jacker has but I'm guessing it is the same year as the motor. with my current set up the gps speed continue to climb along with the rpms my water pressure is over 15 probable 18 to 20

[Savage]

Get your tachometer verified, if the RPM'S are correct, then test a 25P Trophy or Tempest.

[SeaPro Admin]

You should call a reputable prop shop for accurate advice and some will let you demo several props before you buy one

[jdwo2212]

Measure the setback. Just put a tape measure against the transom and see how far the plate sticks out. For prop to pad kust do a search here to figure it out. Ya just need a tape measure and a stick. That helps to know a lot.

[daveb990]

I finally got a chance to check and it looks like the set back is six inches and the prop to pad is 3 1/2 inches under the pad.

[SkidMark]

I have same model number boat but the 2001 with a 200 Merc EFI and with the Tempest Plus 24p and 8" plate....it is a total dog out of the hole. 2 ppl, half full gas and water in livewells.....6-8 seconds when not too warm and when hot.....someone best lean up front to get on plane. My old 25p Trophy Plus is coming outta retirement to get up to date numbers and sent off for Balance and Blueprinting. The older 175 and 200 EFI's had the 2.5 gear case, well I know mine does...and they do well mid to top but not too much torque holeshot. I would stay with the 4 blade if I was you but try a 25p 4 blade to see.

[mhines]

25 tempest..70.3mph....same boat...same motor..1 plug out.....you don't have enough motor to turn a 4 blade prop, AND keep a good speed

[daveb990]

How is your hole shot with a full tank and two people with the 25 tempest ?

[mhines]

I don't have a lot to compare to....I have no issues getting on plane with full live Wells and 2 adults....yes it's a little slower but still manages..