Outboard motor upgrade?

[JohnKorte]

So I just bought a 96, Tracker fun barge 24' pontoon boat. It is in great condition since the owner took great care of it. However it only has a 40HP motor. The tag says it is rated to 120HP. I live at a elevation of 5500 feet. So I am wanting to put 150HP on it. Being the power loss at my elevation I should end up with around 130HP. I dont think there is a lot of difference in weight, good idea? If strength of transom is in question for the added torque how would you strengthen it? Any thoughts or concerns and answers would be appreciated.
Thanks

 

[matt167]

BIA and the coast guard doesn’t care about elevation. And Weight affects a pontoon greatly. Put 120hp on it and it’ll be fast enough to pull a tube and have a little fun

 

[jlh3rd]

Are you talking 2 stroke or 4 stroke . If the 40 is original and a 2 stroke then the placard limit of 120 is for a 2 stroke.
Curious what diameter the toons are. Makes a difference and also why there is a placard with a limit. It's not just for transom, balance is part of it....
FWIW, I have a 24', twin 25" tubes with a 2021 Merc 115 CT, the max placard limit.
With the prop I ran I could pull 5 normal sized teens on two tubes, with 4 normal sized adults on board and throw the teens around.....
....but people exceed the placard.....your boat...

 

[airshot]

The real problem could arise if there were ever an accident. You would automatically be at fault for being overpowered ! Not worth a major lawsuit for negligence. Your insurance company would not approve it either ! Hiding it from them means you lost your coverage when something happens. Pontoon are not designed for high speed, a good 100 hp motor will give you all the fun your toon can handle....safely....

 

[roscoe]

Are you talking 2 stroke or 4 stroke . If the 40 is original and a 2 stroke then the placard limit of 120 is for a 2 stroke.

Why would you say that?
4 stroke outboards have been around for over 50 years.
HP is HP.
The boat should have a hp rating.
And a total weight rating; or a person rating and a gear rating.

 

[racerone]

I think you would want to strengthen the transom.----At one time a 125 HP 2 stroke was about 252 LBS.----A modern 150 HP 4 stroke might be 531 lbs.

 

[Chris1956]

A ponton of that size typically has speeds of about 22mph with a 150HP OB. I would think a 120HP OB would see near that speed, and still be within max HP rating. Hopefully that is enough speed for you.

 

[jlh3rd]

Why would you say that?
4 stroke outboards have been around for over 50 years.
HP is HP.
The boat should have a hp rating.
And a total weight rating; or a person rating and a gear rating.

because it's true, THAT's why I said it. Where did I deny 4 stroke existence?
Do you even own a pontoon boat? I do. And a 4 stroke weighs significantly more than a 2stroke and as some on here have stated there is a placard on the boat with a max total weight limit to not be exceeded and there can be legal ramifications if exceeded. Adding a heavier motor reduces the # of passengers....legally speaking.
So there is a lot more to be considered than just HP, ok?
And no one seems to think about weight on a transom while trailering and how that can affect that aluminum construction....It can also affect tongue weight.......So, I think about these things and try to point it out to people that ask...
And my answer was directed to the OP, not you. He asked for any and all comments so I gave him mine. I want to help him understand what's involved in a re-power......I'm not telling him what to do....
If he spends the money for a big 150 HP 4 stroke, puts it on , and that back end sinks in like crazy....He's spent the money ....and now what?
Not your problem is it. All you have to do is shrug your shoulders, right? And walk away.
He's stuck with it, not you.

That's why I said that.

 

[Scott Danforth]

Unless the pontoon is designed with lifting strakes to get it to plane, a pontoon with 40hp and then replaced with 90hp did nothing but burn more fuel. YMMV

Tracker is not known for stout transom pods under them or strong structures. I would never consider over powering one.

If strength of transom is in question for the added torque how would you strengthen it?

The amount of engineering and work it would require to strengthen it doesn't matter. The factory capacity tag still says 120

If you want a pontoon to go fast, look at some of the 2 and 3 engine sport-toons coming from Forest River . You can get triple 450Rs if you want

 

[racerone]

Aluminum is bad for fatigue cracking.-----Have heard of motors falling off pontoons after welds cracked.

 

[matt167]

it’s legal to replace a 2 stroke with a 4 stroke of the maximum hp. The maximum load capacity is factored with the outboard. It will effect how many extra coolers and crap you bring aboard… also note that a person is 150 lbs per USCG, so you may have less legal person’s capacity based on your passenger weight

 

[jlh3rd]

Unless the pontoon is designed with lifting strakes to get it to plane, a pontoon with 40hp and then replaced with 90hp did nothing but burn more fuel. YMMV

Tracker is not known for stout transom pods under them or strong structures. I would never consider over powering one.



The amount of engineering and work it would require to strengthen it doesn't matter. The factory capacity tag still says 120

If you want a pontoon to go fast, look at some of the 2 and 3 engine sport-toons coming from Forest River . You can get triple 450Rs if you want

This is a correct proven statement from my experience.
I re-powered my pontoon from a 60 to a 115 HP Merc. I gained only a 5-6 mph increase. My fuel consumption increased noticebly.
And it cost me a net of $8000....I did get the performance I wanted, so I'm content with my choice.
There is a lot more to consider with a re-power than just HP....
to the OP, how big is your gas tank.
2strokes burn significantly more than an equal HP 4 stroke.

 

[jlh3rd]

BTW,...bigger gas tank....more weight....

 

[jlh3rd]

just came across this....to the OP.
a person needs to understand the ramifications of their choices.....
a brand new boat and the owner is saying "WTF" already...

 

[roscoe]

No one here ever suggested he over power, certainly not me.
But the fact remains, there has never been a separate hp rating for 2 strokes and 4 strokes.

 

[matt167]

No one here ever suggested he over power, certainly not me.
But the fact remains, there has never been a separate hp rating for 2 strokes and 4 strokes.

Yup. Only to subtract the weight from the total capacity accordingly. Since even with a 2 stroke that needs to be calculated.

 

[JohnKorte]

Wow! Thank you all! A lot to consider trying to power up.

This is a correct proven statement from my experience.
I re-powered my pontoon from a 60 to a 115 HP Merc. I gained only a 5-6 mph increase. My fuel consumption increased noticebly.
And it cost me a net of $8000....I did get the performance I wanted, so I'm content with my choice.
There is a lot more to consider with a re-power than just HP....
to the OP, how big is your gas tank.
2strokes burn significantly more than an equal HP 4 stroke.

I am surprised you only seen a 5-6 mph increase. Thanks for your experience.
I am going to try and find a used or rebuilt Mercury 120HP. I fish Navajo Reservoir a little more speed to get up to the northern part and little more power and speed for wake boarding.
Thanks again for all the input!

 

[Scott Danforth]

Im not sure I would wake-board behind a boat with a cuisinart (propeller)

 

[sangerwaker]

Im not sure I would wake-board behind a boat with a cuisinart (propeller)

Wake boarding would be fine. The boarder is 40-75' behind the boat, depending on the rope length. Wake surfing....that's a different story with a potentially bad outcome waiting to happen. I would never surf behind anything other than a direct or v drive ski boat. Maybe a jet drive, but I've never seen a jet drive with the capability of making a surf size wake.

 

[cyclops222]

Why do people buy a poon toon ? Then expect to repower so it rides as fast as a V hull ? A round hull will NEVER come close to a V or flat bottom hull.