Prop size for 2018 Mercury 115/ 4 stroke - EXPLT ? Looking for a little more speed....

[doctorwedge33]

Looking to get more top end speed out of motor , currently on boat a Black Max 13.25 x 17 prop on a 2019 Tracker 175 Combo Pro Guide / Mercury 115 hp 4 stroke EXPLT

 

[Starbanker]

The Mercury website does have a prop selector tool that you can use. You'll need to know the weight of your boat with it's load added. https://www.mercurymarine.com/us/en/propellers/mercury-propeller-selector
From what I see is that the prop has a much smaller pitch that it could take. What is the WOT rpm? As long as you stay within the engine's normal operating range you can get a bigger pitch prop. The best way to find the right prop is a dealership that will let you try out a prop on the water. A good way to select one would be a prop that will be at the mid-range of the normal operating range, for example if the engine has a normal O R of 4700-5200 rpm look for one that would make your wide open throttle rpm at about 4950 rpm. That would allow for a good top end and enough torque for your hole shot.

 

[Dan Wilson]

I´m running a 19 pitch on my Optimax 115 on a Pro Guide V175 and get about 5200rpm but only get 40mph. I was hoping for 43. I´m not sure what the red line is on my motor

I´d be curious as to what you are getting top end now. Btw, my hole shot is great. So no issues there, even with a full load on board.

 

[Dan Wilson]

The Mercury website does have a prop selector tool that you can use. You'll need to know the weight of your boat with it's load added. https://www.mercurymarine.com/us/en/propellers/mercury-propeller-selector
From what I see is that the prop has a much smaller pitch that it could take. What is the WOT rpm? As long as you stay within the engine's normal operating range you can get a bigger pitch prop. The best way to find the right prop is a dealership that will let you try out a prop on the water. A good way to select one would be a prop that will be at the mid-range of the normal operating range, for example if the engine has a normal O R of 4700-5200 rpm look for one that would make your wide open throttle rpm at about 4950 rpm. That would allow for a good top end and enough torque for your hole shot.

That prop selector came up with the Vengeance 13¨ diameter 18 pitch for me, for top speed and overall performance. I wonder how many mph it would get me? 2? 3?

 

[doctorwedge33]

That prop selector came up with the Vengeance 13¨ diameter 18 pitch for me, for top speed and overall performance. I wonder how many mph it would get me? 2? 3?

Not sure how to reply , we are still under ice / snow so it will be a little while before boat gets out on the water .
I have read everybody is all keen on the Mercury X7 Spitfire more mph , hole shot and overall performance. Was wondering what exact prop pitch and diameter it is

 

[doctorwedge33]

Not sure how to reply , we are still under ice / snow so it will be a little while before boat gets out on the water .
I have read everybody is all keen on the Mercury X7 Spitfire more mph , hole shot and overall performance. Was wondering what exact prop pitch and diameter it is

Also it's a 4 blade prop

 

[Starbanker]

I´m running a 19 pitch on my Optimax 115 on a Pro Guide V175 and get about 5200rpm but only get 40mph. I was hoping for 43. I´m not sure what the red line is on my motor

I´d be curious as to what you are getting top end now. Btw, my hole shot is great. So no issues there, even with a full load on board.

Your operating range is 5200-5750, you are running at the low end which means your 19 inch is as high a pitch you can use.

 

[Starbanker]

Not sure how to reply , we are still under ice / snow so it will be a little while before boat gets out on the water .
I have read everybody is all keen on the Mercury X7 Spitfire more mph , hole shot and overall performance. Was wondering what exact prop pitch and diameter it is

The size of your prop should be engraved on it.

 

[Starbanker]

Also it's a 4 blade prop

Four blade props generally recommended for boats that are bow heavy and heavier overall at a cost of speed. More bite, more drag.

 

[doctorwedge33]

So finally today got boat out on the water, top speed 38 mph gps with full tank and 2 people / max rpms trimmed out 5750 .
Any suggestions to get more speed or is that it ?

 

[byron cooley]

What boat do you have

 

[byron cooley]

For me Laser ll was best, vengeance sucked

 

[doctorwedge33]

What boat do you have

2019 tracker pro guide v175 with a 115 four stroke

 

[byron cooley]

2019 tracker pro guide v175 with a 115 four stroke

You should have more speed than 38gps.
Sounds like way too much prop slip.
My Nitro 640LX has a tweaked 75hp optimax. Has no problem spinning a 22pitch laser II TO 5700 RPM 50MPH GPS with good holeshot.
I know my hull is different but you are loosing speed somewhere.