I bought a 2003 Nitro 750 with less than 50 hours on her. She's a fine boat. She has a 125 HP Mercury Tracker motor. The previous owner apparently hit something and slightly damaged the skeg and it must have caused damage to the prop as he replaced it. He put a 26 pitch prop on it. It's a Mercury Trophy stainless steel prop. This thing is a dog coming out of the whole but scary fast when it comes on plane....I mean SCARY FAST. I have operated fast boats but this thing "gets it on" and in my opinion is unsafe for it's length and beam at full throttle.

I've done some research and it seems that a 23 pitch prop might be better suited for the boat as an all around pitch for the propeller. I am more interested in getting on plane quick with a decent top end speed. I am not going to be racing from fishing hole to fishing hole in competition.

What would you recommend for a good propeller pitch and perhaps how many blades.

My current prop has 4.

definintly stay with a stainless prop  if you wanna better holeshot  try a 19, or 21 pitch prop     a three blade should be  fine and significantly cheaper than a fourblade    goodluck

The question here is what is the WOT rpms? By going down in pitch you are increasing your rpms at WOT. You need to find out what your recommended wot is and then go from there. going from a 26 to a 19 is way too much at once. That would increase your rpm by @1400 at wot. Of course you could be overpropped but not that much. I would guess you need about 23 to be ok. Each pitch change is @200 rpm up or down as a rule of thumb.

Hmmm...23 is okay then?

how many rpm are you turning at WOT? without this, we cant really tell you.

23 should be fine

Thank you all for your answers. I really appreciate them. My boat dealer recommended a 23 but I just wanted to more or less confirm this.

Dizzy and Josh,

Please don't think me rude. I can't tell you what WOT on this boat is. The two times I went for it I backed off before it reached top speed. I have been in fast boats but a 17' bass boat headin' for 60 plus in chop? I don't need to know what WOT is. I do know I need a better prop at low end and forget the WOW stuff.

Thanks guys,

Tom

Tom, the reason both guys asked about your RPM's at WOT was that's the best way to make a determination on what pitch prop to steer you towards.  While I'm sure your boat was running pretty fast, a 125hp motor doesn't quite have the grunt to turn a 26p prop to anywhere near it's potential.  If you were doing 55-60 I'd be surprised, boat speedometers have a tendency to be VERY inaccurate at high speeds.  That said, I hope the 23 helps you out.  If you're not interested in finding the exact prop that will work best on your boat, then stick with what your dealer told you. It should put you in the ballpark.

Thanks Cart7,

I know that speedos on boats are inaccurate but I did not feel comfortable with the speed the boat was going and the handling of it. The lake was choppy and I bailed out before I reached max speed.

My dealer has offered to have me try a variety of props. He recommends the 23 but I can try a variety. I'm trying to work this out with as little trial and error as possible.

I'll try the 23 and see how it goes. If I'm not happy he will let me try others.

Thanks,

Tom

Tom, The only way to find out for sure is at wot. I would have to agree with the dealer and go with a 23 pitch. Turning that 26 is just too much prop for that motor, it will get you moving once you get her on the pad but the motor is probably bogged down. Go for the 23.

Go down a couple of inches and try a three blade stainless.  You will probably find you have more top speed and better hole shot.  Might need to drop the motor about 3/4" if you have it dialed in right for that oversize four blade.

I've not seen anything about what kind of rpm you're turning with the 26" prop and don't know what the gear ratio is on the 125 mercs  but that sounds like a whole lot of prop for that little motor.

Thanks Gents,

The reason you haven't seen me post any WOT posts is that the water has been choppy and  it's been cold. I can tell you that once this boat gets on it's "ride" it is way too fast for it's size and way too slow getting on plane. It's hard to read a tach and speedo at this boat's current max speed when your eyes are watering and you're shivering to beat the band.

I was hoping that tomorrow would be a good day to do a test but 30 to 40 mile winds aren't condusive to good good boat testing on the lake.

I used to run my old 16 1/2' Champion SuperV with the 150 ProV on it with a 26P Yammie 3 blade prop that I used as a backup just for grins.

While that boat had a USCG plate that said it was rated for a 150, there was no way, back when it was made and the biggest 150's were the old Merc Tower of Powers which were rated at the power head,  that it was ever intended to be run with that much 150hp motor.

Normally I ran a 23P prop which made the boat less beastly. That 26P prop made for a wild and scary ride.  

So I am not alone in my insanity? ;D

I own and operate a Prop shop.  based on the information from your posts, I would recommend a 21P with heavy cup.  The lower Pitch will get you up out of the hole and give you a decent low speed performance.  Once you are up at the top, the cup will provide the same thing as running a 24P or 25P for high speed. You can also try going to www.mercurymarine.com/propselector.  This asks you several questions and will give you several options for the motor.  You do not need the WOT to get a good idea as to what you need.