New Prop Selection

[fredcs1209]

Hey Guys,

Current set up:
1750 SuperHawk
2015 115hp Merc 4 stroke
17 Pitch Black Max
WOT RPM 5900
42 MPH
Motor mounted top hole

I am looking at the new Spitfire X7 4 Blade SS

My question is should I get 15p or 17p prop when going from 3 blade to 4 blade/ aluminum to stainless steel?

thanks for your help!

[propmann]

Originally Posted by fredcs1209

Hey Guys,

Current set up:
1750 SuperHawk
2015 115hp Merc 4 stroke
17 Pitch Black Max
WOT RPM 5900
42 MPH
Motor mounted top hole

I am looking at the new Spitfire X7 4 Blade SS

My question is should I get 15p or 17p prop when going from 3 blade to 4 blade/ aluminum to stainless steel?

thanks for your help!

That prop is designed to run within 50 rpms as the aluminum version so I would go with the 17 pitch.

[fredcs1209]

thanks Propman!

One dealer told me that it is a wast of money going SS on such a small motor and that I will not notice any differences from the aluminium spitfire to the SS...is there any truth to that?

[Leanismean]

fred what were your test conditions? #ppl, batteries, gear? I have a 1750 fish hawk with 2015 merc 115 4 stroke 13x19P black max looking at the same choice you are but i don't recall WOT RPM's Mercury test results show my boat with a 13.5x15 spitfire @6000rpms, but searching for more info before dropping $428 on the spitefire X7

[staylor]

Originally Posted by Leanismean

fred what were your test conditions? #ppl, batteries, gear? I have a 1750 fish hawk with 2015 merc 115 4 stroke 13x19P black max looking at the same choice you are but i don't recall WOT RPM's Mercury test results show my boat with a 13.5x15 spitfire @6000rpms, but searching for more info before dropping $428 on the spitefire X7

I don't know if I'd spend the big bucks on SS vs aluminum on a 40-45 mph rig. I would not expect much of a speed gain over a Black Max or Spitfire aluminum- maybe 1 mph, and you have a good chance of running into prop knock at low speeds from the heavier SS prop on a 4S- and prop knock will drive you crazy. As for price, I see that Jaco's Marine has the Spitfire X7 available for $389. currently, www.jacosmarine.com
Doug

[buckhead]

Originally Posted by fredcs1209

thanks Propman!

One dealer told me that it is a wast of money going SS on such a small motor and that I will not notice any differences from the aluminium spitfire to the SS...is there any truth to that?

In my experience with a 115 Opti the aluminum spitfire starts to lose its cup after some hard running so I had to replace it at the start of each season. Top speed would drop from 41-42 at start of season to 37-38 at end of season.
A SS spitfire or Trophy Plus is a much better choice IMO.

[Darrenf442]

Why are you changing ? 42 mph out of a 115 on a 17 + foot boat is pretty good. I know mercury has higher numbers on their performance sheets but that's an empty boat.

[Leanismean]

Buck head do u have input on the trophy vs the spitfire X7 I have a 17P aluminum spitfire and get 6000 rpm and 42mph average load. Looking to get a stainless prop for heavy load and tubing of the two what one and go down a pitch?

[Leanismean]

2015 Mercury 115 4stroke 2.07 on 17' Fishhawk