Promax Propeller on a STV Euro

[4Speed]

Anyone ever tried a mercury Pro Max 4 blade on a STV?
Pros/ Cons?

[engineermike]

I found the promax to perform similarly to a blaster on my eliminator. I believe merc has stated the promax blades are from the pro et, which is similar to the blaster. The biggest difference is the hub size. I did find the promax to carry the bow better than other props like bravo1.

[Beak Boater]

I have a Jack Barsh built Euro running a 225 Pro Max that I bought from a board member that currently is running the 4 Blade Pro Max 29 pitch. I am probably not the best source of information on this as I have just bought the boat and have limited seat time in it, but I will share my observations.
The boat jumps on plane, the prop locks up pretty fast and even with 2 people and full tank of fuel its quick to get on plane. Once running the prop carries the boat well and responds to trim. Mid range acceleration is strong, but then again the other tunnels I owned were a 21 Eliminator and used my sons 28 Skater. The STV hop folks talk about I haven't experienced, accelerating slow or hard, the boat just lifts and takes off that's with the trim at neutral. Not sure if that's due to the prop or a combination of set up and prop. Prop Shaft is 1 1/4 inch above the center pad. Because of my limited seat time I took the boat up in speed in short runs to 70, then 80, and up to 90. At 90 the back left of the boat seems to try to pick up, for lack of a better term. Its not a chine walk like a V bottom, but its like the left tunnel is loosing air pressure letting the boat settle down and pick back up. I ran it up to 92 to see if it was getting better but it didn't so I slowed it down. This may be an issue of my driving and not the propeller, but once it gets around 90 I just tap the trim down a little, from neutral, maybe I am trimming it down to soon, but I would rather learn that way that over trim it. Motor is around 6200-6300 rpms at 92 when I glanced at the tach, boat is still accelerating not sure what the final number will be if I can settle it down. When I ran the slip numbers they were very low.....like 0 so I think the prop is taller than its marked or the tach may be off.
Pro Max seems to be a great all around prop, carries weight well and runs strong in the mid range. Probably my inexperience in the boat is contributing to the moving around at 90, but I ran out of time and space to make any more passes and experiment with trim setting. Hopefully someone will come along and contribute that has more experience than me running this prop, but this is what I have seen so far.

[Brookbbb]

What lower unit are you running?

[Beak Boater]

Torque master with a Bobs nosecone and torque tab.

[4Speed]

My STV has a Sportmaster 1.62 gears

[Brookbbb]

Torque master with a Bobs nosecone and torque tab.

With a low water pick up style lower like you have I would personally lean towards surface piercing/over the hub props instead of through hub props like the promax to take advantage of your lower. You'll be able to raise the engine higher, creating less drag in the water which in turn will make you go faster and create a smoother ride. If you were running a stock torque master then the promax would be a great option.

[wicheckmate]

With a low water pick up style lower like you have I would personally lean towards surface piercing/over the hub props instead of through hub props like the promax to take advantage of your lower. You'll be able to raise the engine higher, creating less drag in the water which in turn will make you go faster and create a smoother ride. If you were running a stock torque master then the promax would be a great option.

the promax is both as it has a small diameter hub so its over/through.. Its not as large of a hub like the bravo nor complete over hub like the old pro-et. The only thing limiting the pro-max is it's blade diameter as far as engine height goes.