Pontoon Boat & Deck Boat Forum

I have the new Mercury 150 4 stroke on a 25' Starcraft tritoon. I first started with a 15 3/4 x 15 prop with did not work out very well. Next I switched to a 15 3/4 x 13 extra cup and it works alot better but the problem is that my WOT rpm are only 4950 and that dealer wants me to try a 11 pitch prop to get my rpm's higher. What WOT rpm are other owners getting and what prop are you using?

I presently have a 15x15 4 blade ss prop on my 150hp 4 stroke Merc and I only get 5150 rpm's
My boat is at the dealers for it's 20 hour check and the salesman new about my low rpm's and showed me a prop on another toon with a 150 hp Yamaha that's turning 5,900 rpm,s at 37/38 mph.
The prop I believe is 13p x 15" dia. 4 blade that's made by Yamaha but doesn't say Yamaha on it.
I should be getting my boat back in a day or two and then I will try it out and let you know what the results are. I hope it works for me.

First of all, you didn't mention if you're talking about aluminum or stainless props. There's sometimes a performance and rpm difference between the two. Also, are you talking factory props, or aftermarket (Michigan Wheel or equivalent?)

If you're talking stainless, the Mercury Enertia appears to be their best 3 bladed prop for all round use. That's what Mercury equips them for boat testing in magazines. Yamaha uses their Reliance series of props for boat testing in magazines.

You didn't say if your tritoon had strakes. If not straked, you'll probably have to drop down in pitch from what you'd think you need.

My next door neighbor has a 22' Harris tritoon (w/strakes) running a 14 pitch Enertia. That prop is available inch by inch for a proper fit. I often see some with 15's and some with 14's with 150 hp motors.

Some dealers are better than others when it comes to setting up motors. If the motor is at the wrong height (too low or too high) on the transom, you can forget ever getting the prop right.

Also, some manufacturers' customer service departments keep track on what props perform correctly on which hulls. Sometimes, local prop shops can give free advise on what props to use, especially if you're going to purchase propellers from them.

Good luck!

Running a 15 enertia on the 150 opti. Just right rpm wise. May have been able to handle a 16 enertia but the 15 was close enough. Oh 17p was way to much only 5300rpms but only about 2mph slower.
doc

I'm running the Mercury Black Max Aluminum (extra cup part number 48-78116CP1) 15 1/4 x 15. 5600 RPM, 38/39 MPH. My dealer played with about 9 different props, some SS. I didn't want to go the SS route. He also played around with lowering and lifting the engine as well. I decided to go with the best aluminum set up.