Tritoon Conversion

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gobeernet
Posts: 27
Joined: Thu Jan 29, 2015 9:27 pm

Tritoon Conversion

#1 Post by gobeernet » Mon Feb 23, 2015 11:54 am

I picked up a 22' Bennington Pontoon and have the itch to convert to Tri-Toon for performance and rough water reasons. Current toons are 22" or 23" diameter and approx. 22'6" long. No Strakes. 115 Mercury. Currently 22 mph at WOT/max RPM with a moderately bent 15 pitch SS 3 blade. I'm looking to get 30mph and handle rough water, as the lake I will be on is busy and windy.

1. What is the optimum center toon to install on this rig - length/diameter/strakes/transom length/etc?
2. Should the center toon sit protruding, flush or behind the side toons? Seems like new OEMs are doing all three.
3. Does the motor need to set back from the side toons? Again - new OEMs are doing flush and set back.
4. Does under skinning give as much benefit to a tritoon compared to a pontoon?

I'm planning on keeping my current single axle trailer. Can the new toon "hang" from the floor when on the trailer or are additional bunks required?
It floats, I'm happy.

Bamaman
Posts: 3679
Joined: Fri May 06, 2011 1:44 pm
Location: NW Alabama--Tennessee River

Re: Tritoon Conversion

#2 Post by Bamaman » Mon Feb 23, 2015 2:09 pm

With your hull and engine combination, I would have thought a 15 pitch prop would be too much. What kind of RPM's are you experiencing? Is your 115 hp a 4 stroke or is it a 2 stroke? How old is your motor?

23" toons are somewhat rare today, with 25" toons being more common. Have you carefully measured the toons? What year is your boat?

Is your speed computed by GPS, or is it by the old style pitot speedometer?
'12 Bennington 24' SSLX Yamaha 150

gobeernet
Posts: 27
Joined: Thu Jan 29, 2015 9:27 pm

Re: Tritoon Conversion

#3 Post by gobeernet » Mon Feb 23, 2015 7:15 pm

Bamaman wrote:With your hull and engine combination, I would have thought a 15 pitch prop would be too much. What kind of RPM's are you experiencing? Is your 115 hp a 4 stroke or is it a 2 stroke? How old is your motor?

23" toons are somewhat rare today, with 25" toons being more common. Have you carefully measured the toons? What year is your boat?

Is your speed computed by GPS, or is it by the old style pitot speedometer?
Boat is a '99 Bennington 227FS.
Motor is a '99 Mercury 2 stroke. RPMs were 5,000 as best as I can remember. Max RPM per motor placard is 5,250.

Data plate on the boat indicates 22"-23" toon size. Best I could tell with a tape measure was 23". I'll hang a string over them tomorrow and find out.
The boat came with a Ballistic 13 5/8" x 15. It had a few dings and a bend in it. I just got it back from the prop shop.

Speed was GPS from a cell phone. Measured both directions on calm water with virtually no wind. Read 22mph most of the time, flashed 23mph every so often.

FWIW, Mercury prop selector recommended a 15.91 pitch for "good overall performance" at 5,000 RPM on a 2750lb pontoon. It listed 15, 16 and 17 Alum and SS props.
It floats, I'm happy.

gobeernet
Posts: 27
Joined: Thu Jan 29, 2015 9:27 pm

Re: Tritoon Conversion

#4 Post by gobeernet » Tue Feb 24, 2015 7:41 pm

I've located tubes. So far I have 2 options for about the same price.

A.) A factory 25" diameter center tube with strakes and set back transom. I really like this options since it has strakes but I assume this would require moving my helm back for controls to reach. Also the 25" toon would sit 2" below my current 23" toons. Is this good or bad?

B.) A made from scratch 23" U-shape tube, 25" tall w/o strakes and the motor flush with the back of the boat. This seems like the easiest solution as motor is in the same place. This seems like an unbolt/rebolt situation.

Opinions?
It floats, I'm happy.

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ToonGuy
Posts: 968
Joined: Tue Feb 08, 2011 9:34 am
Location: Lake Wawasee, Northern IN

Re: Tritoon Conversion

#5 Post by ToonGuy » Wed Feb 25, 2015 6:11 am

As you already know B is less complex, so you will gain some but not nearly as much performance and A. IMO, if you're going to the trouble I would choose A without hesitation. Your harness will most likely be long enough, you will probably need longer shift/throttle/steering cables. You're talking less than $200 bucks for those, and a little more work for a lot more performance.

And absolutely under skin it when finished!
Just one boat...after another, after another :-)

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