What prop?

[wildkat7]

I have a 17.5 pro team tracker with a 40hp Merc 2 stroke. The prop that is currently on it is an aluminum dinged up old one. What should I be looking for on this rig. No jackplate or anything special. I want the most speed out of this little motor I can get.

[bassfisher444]

You aren't going to get much more than high 20s with an undersized motor like that. Just get a cheap aluminum prop to replace it with.

[tcesni]

Merc has a good website for making prop selections and like any other boat you want to be very near the maximum recommended rpm at WOT. If there is a stainless option you might look around on EBay for that prop as there probably aren’t many sold for that motor and you might find a deal on some new old stock. I have two stainless props and only paid $150 for each of them by looking on EBay.

[FloridaFlyer]

I have had flats boats similar. My tech who has been doing outboards for about 40 years and who I really trust, has always talked me out of stainless on smaller motors like your 40.

He says that the lower unit is not as big and strong as those on bigger motors like 115 or 150. He says that aluminum will bend or break if you hit something hard and stainless won't. He has fixed a lot of smaller lower units that would not have broken with aluminum vs. stainless. I always took his advice. There is nothing much to gain and a lot to lose.

Solas makes about as good of an aluminum prop as you will find. Buy one and get the old prop fixed for a spare.

[GeauxTide]

I had a similar boat, although not as heavy. I had a 13" SS Vengeance 4 Blade and it did very well. That is phooey on the weaker lower units. I lived in LA and we constantly ran into stumps. A generation of Commercial Crawfishermen used that 4 Cylinder Merc.

[R2Tracker]

Mercury Spitfire, use the prop selector to find the right pitch for your application.

Do you know what's on it now... If I were to guess its likely a Mercury Black Max in maybe 12ish pitch?

[wildkat7]

Mercury Spitfire, use the prop selector to find the right pitch for your application.

Do you know what's on it now... If I were to guess its likely a Mercury Black Max in maybe 12ish pitch?

That was how I tried to find out but couldn't see anything written, engraved anywhere.

[Coastal Mountaineer]

Modern stainless props use hubs that slip if the prop hits something, minimizing any damage to prop. There are several Mercury and Solas props that will work with your rig.

[rangerguy35]

I would just upgrade to a 4 blade if you haven't already. I forget the prop I had on my 60 hp Merc. But the 4 blade was amazing hole shot and I really didn't lose much speed on the top end. Like 1 or 2 mph. I always used aluminum props on that boat cause they are cheap and I didn't think a stainless would give me that much better performance.

[Extremeboating]

You aren't going to get much more than high 20s with an undersized motor like that. Just get a cheap aluminum prop to replace it with.

This right here. The Tracker PT175 (TXW, TF) is a large boat to begin with and will not be making much headway without either a 60 HP or a 75 HP on it.

You will not get higher then high 20's on it for sure and there is no point in trying to optimize speed on it due to the lack of horsepower.

If the 40 HP is a Bigfoot/ CT version then I can help you, but outside of that, it would be a fruitless venture.

[Extremeboating]

Modern stainless props use hubs that slip if the prop hits something, minimizing any damage to prop. There are several Mercury and Solas props that will work with your rig.

Yep. Modern Mercury outboards use a square hub design style prop that are meant to break before the prop can cause damage to the lower unit if and when you hit something. It's the rubber hub style props you need to stay away from because those will not slip and give way anywhere near as close as the plastic square hubs do. This message is intended for the OP by the way.