How Many Horses Can Take A 16 Ft Larson

[trikefloats]

I had a 50 hp engine on my 16 ft mid 80's Larson. This engine is history now. I am thinking the next one to be between 75 to 120hp. Is 120 too much. I have been told that if I am using a bigger engine it will use less gas, especially if I load the boat with 2-3 people on board and a skier behind. Of course the smaller engine will be more efficient if I go on a trip only me and my 120 lb wife.
Your suggestions will be of extreme value to me.

 

[NelsonQ]

Re: How Many Horses Can Take A 16 Ft Larson

Check the tag on the boat for the max HP rating. With a 16ft, I'd guess around btw 110-125HP as the max size.

And yes, the more HP you can add, the less throttle you'll need which should translate into easier gas consumption. However, how its prop'd, the load in the boat, and if you have a lead hand like I do and use WOT regardless, the fuel savings will be exchanged for more speed.


I'd guess anywhere above a 90HP and you'd be happy (if speed isn't your primary concern) which it doesn't appear to be.

 

[haskindm]

Re: How Many Horses Can Take A 16 Ft Larson

A mid-'80's boat should have a capacity plate that will indicate the largest horsepower outboard that should be installed on a boat. There are many reasons that this maximum should not be exceeded, both legal and safety reasons. This has been discussed and debated in many threads. A search should result in several hours worth of reading. It MAY be true that - for a given speed - a larger motor MAY be more economical than a smaller motor. But the temptation will be take advantage of the increased horsepower to achieve additional speed. A 120-HP motor at WOT will use more fuel than a 50-HP motor at WOT, that is a given. That said, many new motors are much more economical than the engines that were built a few years ago. I recently upgraded from an older 16-foot boat with an 80-HP motor to a newer 18-foot boat with a 115-HP 4-stroke. If anything the new boat uses less fuel than the old boat and has a considerably faster top speed.

 

[tashasdaddy]

Re: How Many Horses Can Take A 16 Ft Larson

going over the recommend hp rating on the plate can have some legal problems later.

The United States Coast Guard has an opinion on this frequently asked question, and their answer from their website is reproduced below:
Can I use a bigger motor on my boat than what it's rated for?
It is not a violation of Coast Guard regulations to install or use an engine larger than specified on the capacity label, but there may be state regulations prohibiting it, and restrictions from your own insurance company regarding this.
There are no Coast Guard regulations against exceeding the safe loading capacity, however, there may be State regulations or restrictions from your insurance company which prohibit this. There is a Coast Guard regulation that gives Coast Guard Boarding Officers the power to terminate the use of a boat (send it back to shore) if, in the judgment of the Boarding Officer, the boat is overloaded. There is no fine for this, unless the operator refuses the Boarding Officer's order. We certainly hope that you will abide by the rating, as overloading may lead to capsizing or swamping of the boat.
NOTE: The Coast Guard Capacity Information label is required only on monohull boats less than 20' in length. The label is not required on multi-hull boats, pontoon boats (catamarans), or on any sailboats, canoes, kayaks, or inflatable boats, regardless of length.
As the Coast Guard mentions, local regulations may apply. For example, in the state of Ohio one should be guided by this regulation:
Capacity Plates
(ORC 1547.39 & ORC 1547-40)
No person shall operate or permit operation of a watercraft in excess of any of the stated limits on the capacity plate. When no capacity plate exists, no person shall operate or permit operation of a watercraft if a reasonably prudent person would believe the total load aboard or the total horsepower of any motor or engine presents a risk of physical harm to persons or property.

 

[109jb]

Re: How Many Horses Can Take A 16 Ft Larson

It has been covered tons of times. You should go by what the horsepower rating on the capacity plate says. No more than that.

 

[zach103]

Re: How Many Horses Can Take A 16 Ft Larson

look up yoru boat on google. there should be a link to info on iboats. i did it for my larson and got 150hp max. mines a 17' 1986

 

[waterone1@aol.com]

Re: How Many Horses Can Take A 16 Ft Larson

The capacity plate would be a darn good guide. With that said, are you planning on buying a new motor ( or fairly new) or an older, used motor ?
Part of the reasoning behind the capaity plate on your boat is motor weight. Newer motors are getting more horsepower out of lighter packages. I've always been into larger cabin cruisers, but my dad had a 17 foot open bow ( fiberglass) at his lakehouse,and that thing did very well with a 70 hp merc. If I were to choose the motor it might have been a 90 - 110 hp, but no more.