TRANSOM SWAP

You know the drill..

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wc9550
Posts: 52
Joined: Sun Oct 22, 2017 5:38 pm
Location: Montgomery, IL

TRANSOM SWAP

#1 Post by wc9550 » Sun Aug 12, 2018 1:24 pm

Ok guys I know there is a bunch of info on this site and I am wondering about something. I have an aluminum transom on my boat (1996 Sweetwater at 20 feet). The transom is great no issues, but only rated for 75hp. I have found a guy selling another transom rated for 150hp. I am wondering if anyone here has swapped their transom to get more hp on their boat? Also mine is a pontoon and not tritoon. The measurements are about double the size of mine (twice as wide and twice as long). Any info is appreciated. This may be my winter project for the boat. Thanks guys
2019 South Bay 224SB2 3.0 tritoon with 2019 Merc. L200

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Rick McC.
Posts: 419
Joined: Fri Mar 31, 2017 7:12 pm
Location: Weeki Wachee, Fl

Re: TRANSOM SWAP

#2 Post by Rick McC. » Sun Aug 12, 2018 7:45 pm

Well, I’m pretty sure that the max HP rating of any boat is based on more than just the transom design.
Rick

Sights are for the unenlightened.

boocat
Posts: 269
Joined: Sun Aug 28, 2016 8:09 am
Location: Texas Hill Country

Re: TRANSOM SWAP

#3 Post by boocat » Mon Aug 13, 2018 6:35 am

Yep. And I really didn't want to say it but it kinda sounds like a borderline can of worms to me but I don't know enough about major rebuilds.

willy13
Posts: 248
Joined: Sat Dec 22, 2012 8:23 am
Location: Canandaigua Lake in NY

Re: TRANSOM SWAP

#4 Post by willy13 » Tue Aug 14, 2018 8:26 am

The biggest problem will be getting a dealer to sell you a new outboard with a hp over your capacity plate rating. I have a Fire and Marine tri-toon and they do not issue a capacity plate unless asked for. The reason is that capacity plates are only required on boats less than 20 ft. They are sending me one because no dealer would sell me an outboard without a capacity plate. :lol3

You can certainly make the transom structurally sound on your pontoon boat. Make sure there are no current stress cracks starting on the cross members. If the cross members are made of channel aluminum, make sure it is structural aluminum and not architectual aluminum. You could also add additional cross members if they are only 24 inchs off center in the back.

There is a hp calculator for the size of a boat. It is (L x W)*2 - 90. According to this formula, your boat can handle 230hp. I know I know its just a formula, but go look at the crazy hp these bass boats have.

The next issue will be your insurance company. Some care and some don't. If its just going to be you driving the boat then thats a plus. Hell my dad never even insured any of his boats.

wc9550
Posts: 52
Joined: Sun Oct 22, 2017 5:38 pm
Location: Montgomery, IL

Re: TRANSOM SWAP

#5 Post by wc9550 » Tue Aug 14, 2018 2:55 pm

Thanks for the replies guys. My capacity plate is a sticker next to the steering wheel and it’s completly blank. I contacted Godfrey and they gave me a brochure for the year of boat and I found my exact model. It says it’s rated up to 75hp. I may have to do a lot more research on this topic to see if it’s possible or if it’s better to upgrade boats. Thanks again for the input guys.
2019 South Bay 224SB2 3.0 tritoon with 2019 Merc. L200

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