Dialing in the tritoon!

[Rynobull]

Just picked up my new tritoon last weekend. Had to break it in running under 4k rpms for the first 2 hours and now I have finally let it eat a few times.

2019 Bentley 243 Navigator
2018 Suzuki 350 duoprop
Most all options with the bigger lifting strakes
4 inch Seastar Xtreme jackplate
3/4 length center tube.
Reinforced aluminum transom.
27 pitch props

At full jack the prop shaft center is even with the toons.

At first I was having a hell of a time breaking 55 mph... it was proposing horribly!!! After some seat time I found out I was jacking it up too high and it causes the porpoises. It runs best about 3 inches below tubes. Runs 60 mph even on gps with me in it full tank of gas and all the anchors, bimini and all the crap we carry boating.

I am only pulling 5600 rpms (recommend 5700 to 6300!) and with 2.29 gear ratio that's 5 percent slip! I need to bump down to the 25.5 pitch props, remove some weight from her and take the bimini off (even rolled up that has to cause some drag)

I'm guessing mid 60s is in the cards. I was hoping to eventually hit 70... but that's a very long shot!

[pbxcomm]

I would look at a SOLAS Prop for your setup.. You would not be disappointed at what the SOLAS offers in performance.
I don't have a tritoon (two tubes) but have tested literally a dozen props on my toon and not one (including stainless) would touch the SOLAS.

[99fxst99]

pbx, what size prop are you running?

[RSWORDS]

It blows my mind how many dealers dont prop test new boats. You are the 3rd new boat in two weeks that I've seen/heard of being propped wrong. I'd make them put the proper props on it. Those props are not cheap

[pbxcomm]

pbx, what size prop are you running?

My rig, much less than yours however, for whatever reason the SOLAS turns out to be very good performing prop for pontoons.
Here is what I have:
22' Rivera Cruiser (completely restored)
125 HP Mercury 2 Stroke 2+4 (2.07:1 gear case)
13 1/4" D x 18" P SOLAS
37 MPH (GPS) @ 5400 RPM

Seems speed, RPM, HP is relative on pontoons. Slip is always an issue. Currently I am at 16% slip, if I was to change SOLAS props (perhaps a 19 or 20 P) @ 40 MPH I would be right at 10% slip. I never achieved these numbers with ANY other props I spun and I spun maybe more than a dozen.
One other note: the SOLAS aluminums average $100.00.. I tried Stainless propos up to $450.00. So, @ $100.00 for the SOLAS, you could try a few and have a few left in your wallet.

[pbxcomm]

Just picked up my new tritoon last weekend. Had to break it in running under 4k rpms for the first 2 hours and now I have finally let it eat a few times.

2019 Bentley 243 Navigator
2018 Suzuki 350 duoprop
Most all options with the bigger lifting strakes
4 inch Seastar Xtreme jackplate
3/4 length center tube.
Reinforced aluminum transom.
27 pitch props

At full jack the prop shaft center is even with the toons.

At first I was having a hell of a time breaking 55 mph... it was proposing horribly!!! After some seat time I found out I was jacking it up too high and it causes the porpoises. It runs best about 3 inches below tubes. Runs 60 mph even on gps with me in it full tank of gas and all the anchors, bimini and all the crap we carry boating.

I am only pulling 5600 rpms (recommend 5700 to 6300!) and with 2.29 gear ratio that's 5 percent slip! I need to bump down to the 25.5 pitch props, remove some weight from her and take the bimini off (even rolled up that has to cause some drag)

I'm guessing mid 60s is in the cards. I was hoping to eventually hit 70... but that's a very long shot!

I'm reading conflicts in prop, RPM, speed and slip.
The porposing is from slip no doubt. You too high on the jack plate.
I'm not sure SOLAS manufactures dual props but could have a look.
25 P may be too low pitch, I would go with a 13 1/2 x 26 (13 1/4 diameter minimum), if possible a 14 x 26.
What is the diameter of your 27? Maybe be too much diameter?
I would not try a 4 blade if your seeking top end, which it appears you may be.