Will not reach Max RPM range

[Viator]

Hi I am new to the pontoon owners club, I recently purchased a Suntracker Party Barge 21 with a mercury 60 bigfoot. I upgraded to the stainless steel prop and they installed a Power Tech WBH3R12PM135 prop. After breaking in it per the manufacturers specs. I went for it and pushed the power past 4500rpm. To my surprise the RPM only rose to 4700 RPM at wide open throttle. We were going 15 mph and had 6 adults on board and glassy water. I know the WOT rpm should be between 5500-6000. This was quite disappointing as we were truly hoping the toon would go 20mph. We purchased it with the intent to be the docking area for our PWC and ski boat and pulling tubers. I know the prop should be the first thing to look at. So, the numbers posted above are stamped on the prop. Not to sure how to decode it to find out the pitch. Any info or advice is greatly appreciated. Also before you purchase any boat from the Bass Pro Shop in Denham Springs, Louisiana please contact me and I will tell you about my not so good experience. Thanks Jessie

[trott46]

With pontoons being pushers the more weight aboard the more water you push. I would take it out on your own and see where you are in rpms. If it is going to be a normal thing to have 6 adults on board then you may want to go to a smaller pitch prop to reach your max rpm range.

[Viator]

Thanks, I did go out by myself went to 5000 rpm and 18mph, I am going to contact the prop manufacturer tomorrow.

[mike]

about the only way to do it is get your dealer to lend you a selection of demo props to try out, then buy the one that works best for your boat/motor combo! Its really hard to predict which prop is best... Welcome, you are gonna love that boat!

[Russ]

I was in the same boat ( ) you are on needing a different prop but I was above my target RPM. I got the same answer from three different sources (Piranha prop website calculator, the guys at Piranha, and the turningpointpropellers.com site calculator). I have a 18' Party Barge with a 50HP 2-stroke. My boat was doing 19 MPH by GPS at ~5800 RPMs on calm water with only me and no extra stuff. I also wanted to increase my unloaded top end so all three sources recommended a decrease in overall prop diameter and an increase in pitch.

My old prop was a 13" diameter 8" pitch. I went with a Piranha and got a hub assembly with 12" diameter with 11" pitch blades (pretty much the recommendation from all 3 sources) and 11.5" diameter with 13" pitch blades (an off-chance recommendation that may give me more top end from the guys at Piranha). They also said I could send back and swap for another set too if I wanted until I got it right. I haven't had a chance to get the boat out since I got the new prop so I can't tell you the results yet.

It sounds like you'll want to go down in pitch and up in diameter from what I've gathered, but see what the prop calculators say first. The http://www.turningpointpropellers.com calculator has a few more inputs that help get a better idea of the normal conditions of the boat, including average passengers and extra weight. Only down side to the turningpoint page was they didn't list the Suntracker brand on their list for my boat's year that I could find. I looked under just Tracker but those were just fishing boats. I think I just ended up using an 18' Harris for the calculations.

[Viator]

Spoke with power tech, they told me I need a 10 pitch prop. I am currently running a 12, spoke with the dealer where I bought the toon and they are going to swap it out.

[dockholiday]

Spoke with power tech, they told me I need a 10 pitch prop. I am currently running a 12, spoke with the dealer where I bought the toon and they are going to swap it out.

Good deal......There are lots of people that never get the correct or top performance from their boats, simply because they were not properly rigged from the dealer.
doc

[lakerunner]

Just keep trying props till the right one works. My new E-Tec took 4 tries before I got the right performance.