What size Mercury motor on 24 ft tritoon

[skipg]

I am checking out a 24 ft Sun Tracker fishing barge tritoon. It comes with a 115 Mercury Pro XS Four stroke with "Command Thrust".
I was wondering (for inshore use in the Gulf) if I should consider a step up to a 150 hp. The option available is the 150L Mercury Four Stroke.
My question is - how do I compare the motors and is it really worthwhile as far as improved speed or efficiency?
Thanks

 

[Scott Danforth]

welcome aboard

its a pontoon... you can push it with a 9.9hp motor

as far as improved efficiency, the 115 will burn much less fuel than the 150

if you want to step up to the 150, then do so. it will burn more fuel, make more noise and go slightly faster

however as for fishing, I found that having the anchor down, a beverage in my hand, and being in the right spot is what catches fish. not the size of the motor that got me there

 

[ahicks]

Make me understand why you're considering a tri-toon. Often, that explanation will offer up good reasons why you would go with the maximum amount of power available. No need for maximum performance = questionable need for a tri-toon.

 

[skipg]

Thanks for all the replies. I am considering a tri-toon based on recommendations of other owners; they say it is the only way to go for the Gulf. The only reason I considered a larger motor was to cut down on travel time to various locations and back, especially if the weather started acting up and they say I need enough power to move the 3 pontoons.

 

[ahicks]

<<<" they say I need enough power to move the 3 pontoons">>>

That's it in a nutshell. Instead of having a max speed of 20-25 mph, with a 150, you can cruise at those speeds. The 150 on a regular 2 tube toon would run very low in the back - not something you'd want out on the Gulf. The tritoon carries the bigger/heavier 6cyl. engines easily....

 

[82rude]

A buddy has the 150 merc and tritoon and loves it big time.Sure moves along nicely,lol.

 

[HotTommy]

Food for thought:
At first glance the only drawback to the 150 is the higher initial purchase price, but there are a few other things to consider. Let&#146;s start by acknowledging that there is no reason at all to opt for the 150 if you are not going to use the extra power it has over the 115. So consider the impact on range and budget of operating at full throttle. The common rule-of-thumb is one gallon per hour per ten horsepower. So expect to use 15 gallons per hour at full throttle with the 150. Divide the capacity of your fuel tank by 15 to see how many hours you can operate at full throttle. Divide that by two if you will be offshore and can&#146;t easily stop enroute for fuel. So, for example, a 60 gallon tank would allow you to go out about two hours before you&#146;d have to start back. If you wince at the thought of refilling a 60 gallon tank, then perhaps the 115 is a better choice.

A second consideration is weight. The 150 is heavier and might require you to carry a heavier fuel load to make use of its extra power. Heavier boats displace more water and require more power to push through the water. That third toon also adds weight and displaces more water. All things considered, I would expect top speed with the 150 to be 3-6 MPH faster than the 115 while using about 30% more fuel.

In the end, the stability of the tritoon and the ability to achieve a higher top speed to outrun an approaching storm with the 150 might be the best reason to choose that combo for offshore use. But there are pros and cons to both options.

 

[Chigwalla]

...there is no reason at all to opt for the 150 if you are not going to use the extra power it has over the 115...

Unless you want to be able to cruise at a lower power setting, increasing reliability and longevity. Amortized over the life of the engine, the initial higher cost now is probably going to be less than having to repower sooner because the powerhead has been working harder. You'll also get more on resale, though you never want to bank on that.

The common rule-of-thumb is one gallon per hour per ten horsepower.

I run twin 150s (2 yrs old, 900hrs each) - if the OP can cruise at 60% throttle, he will be burning about 6 gal/hr.
The 115 running at 80 or 90% will burn more...but probably not significantly.

All that being said, with the hours most people put on in a year, it won't really matter.

You didn't hear it from me, but keep an eye on Merc at the Miami boat show: the 150+hp non-Verado hole in their lineup is finally being plugged.

When people ask me about repowering their boats, my stock answer is to buy the most power they can afford up to what the data plate says.
The fact that the mfr specs a 115CT for the base engine suggests they're trying to hit a price point with a smaller powerhead.
Generally speaking, never take the base power option on any vehicle, especially boats.

Reserve power is peace of mind.

 

[ahicks]

Lot's of good points!

"I run twin 150s (2 yrs old, 900hrs each) - if the OP can cruise at 60% throttle, he will be burning about 6 gal/hr.
The 115 running at 80 or 90% will burn more...but probably not significantly."

I've noticed something very similar, and it may go hand in hand with fuel usage thing I like to use (one gallon per hour per ten horsepower at WOT). I'm thinking it takes X amount of power to push a hull at any particular speed. So if we put some numbers on that, lets say our trusty old 50 will push our boat at 18-19mph at WOT, we can say that we'll be burning about 5 gallons per hour at that speed. The Honda 90 engine that just replaced that 50 recently, will very likely be burning the same amount of fuel (5gph) at 18-19mph, with a slight variance due to the fact it's a 4 stroke (and the fact the 90 is heavier.)

Same story at low cruise (idle, just off idle) speeds. The Honda is not using any more fuel than the J50 it replaced. Maybe less....

Point being, there's no fuel usage penalty for going with the bigger engine. What is gained with the bigger engine is more performance potential. That extra performance WILL cost you, but only when/if you use it! ;^)

 

[Illinoid]

That one day a storm pops up, there is a lot of lightning and you are racing back to safe harbor, you will wish you had bought the bigger motor, regardless of the price.

 

[icwingman]

I am checking out a 24 ft Sun Tracker fishing barge tritoon. It comes with a 115 Mercury Pro XS Four stroke with "Command Thrust".
I was wondering (for inshore use in the Gulf) if I should consider a step up to a 150 hp. The option available is the 150L Mercury Four Stroke.
My question is - how do I compare the motors and is it really worthwhile as far as improved speed or efficiency?
Thanks

I have a 2017 22 dx fishing barge. 115 ct mercury. Run at 30.9 mph 6000 rpm cruises 25 mph easy. I go 20 to 30 miles out in gulf on a regular basis weather permitting. Would not have it any other way. Boat is very sea worthy and really enjoyable. Was gonna get the 24 tri with the 150 but am satisified with the 22 and i saved alot of bucks.