Will a 50 hp fit on 40 hp transom

[tjh79]

Ok so i have a 1985 lowe 16' superior v aluminum boat. Transom rated for 40 hp and boat carry capacity is like 975... now i normally wouldnt do this BUT i am stripping boat down installing a sealed sub floor with aluminum diamond plate with sheet foam under floor from bow all the way untill under rear seat (14' subfloor) no water gettin in... then casting deck from front bench (3 total) to bow, middle bench is being widened 10 inches front to back to install multi compartment live well... now good stuff rear transom is getting pulled apart raised 2.5 inches (17.5 now going to 20) reinforced into sides, bottom and tied into rear bench seat... also installing 2 pontsons .65 cf each should add atleast extra 75 lbs capacity to support motor and to top it all off changing from tiller to side console... now will a evinrude 50 hp motor be to much and or be dangerous... now im not goin to be sellin this anytime soon and im NOT a full throttle wide open guy but i do plan on fishing areas with a bit more current.... motor and controls were free so...

 

[tjh79]

Oh and its a 1982 model evinrude that only weighs 12 lbs more then the 30hp mercury i was lookin at
180 lbs is what evinrude weighs

 

[Scott Danforth]

many outboards have the same mounting dimensions, so many will fit.

however your capacity tag has a max rating based on the width and height of your transom. so if your boat has a 40hp rating, the most you can legally put on is 40hp.

 

[Watermann]

Welcome aboard Sea :wave:

Are you sure the boat is only rated for a 40 HP motor. Reason I ask is most the 16' Sea Nymphs and Lowes are rated at 70 HP as is my little 16' SN.

 

[Frey0357]

I found this online for your boat, assuming that I have found the right one:

http://www.abos.com/Value/551770

You may find that even the 40hp is too much! Raising the transom and not continuing to strengthen the transom may also be too much for this boat.....

Got any pics of the transom area?

Thanks....Frey

 

[lckstckn2smknbrls]

With the major changes your making to the boat negates the info on the plate. Adding 10 hp doesn't sound out of line for the new configuration.

 

[TruckDrivingFool]

With the major changes your making to the boat negates the info on the plate. Adding 10 hp doesn't sound out of line for the new configuration.

It may not in the eyes of an inspecting government agent.

 

[tjh79]

Its a old motor that i promise you doesnt put out 50 hp anymore and its just to get me by for the summer... in sept im buying a 30hp mercury jet drive... im building it up sp it will last me MANY MANY years... no wood, all aluminum, even transom is gettin a extra 3/16 aluminum sheet, transom will be tied into and supported to every possible point....

 

[tjh79]

And waterman are boats are identical hulls but mine has 3 bench seats, thats why im welding in a all aluminum subfloor, id boxing out entire rear and tying it into transom

 

[jbcurt00]

Is your Lowe a welded hull or riveted?

And S Sea, please check your Private Messages

 

[tjh79]

Riveted

 

[jbcurt00]

Iboats has boat spec pages too:
http://boatspecs.iboats.com/

I wouldnt recommend overpower your hull, regardless of whether it is a poorly/under performing OB or not.

You're adding pontoons/sponsons along the hull sides or rear mounted pods?

 

[tjh79]

Mod EDIT
Sponsons will be rear mounted
The problem is i dont know what mine is rated for.. no plate... im just going by what my buddies says and his is 3 years older then mine, mine is built better personally and his is rated for 40
His is 1985 mine is 1988 lowes superior v
but i guess i just need to sell it all and start over then..

 

[nurseman]

There are formulas available to calculate how much HP your boat can handle, based on length and width.
Here is one example of such a site.

http://newboatbuilders.com/pages/hp.html

 

[jbcurt00]

Riveted

Then I recommend riveted changes not welded.

I dont know what grade aluminum Lowe uses, 5052?

 

[Watermann]

Then I recommend riveted changes not welded.

I dont know what grade aluminum Lowe uses, 5052?

5052 would be my bet and for the boat to be 16' and as light as the specs say the sides would be less than .080 which would make it very difficult to get good solid welds. Solid rivets would be best to add structure to the craft.