Twin 90 etecs installation

[joatmon]

I just bought a 95 lund 1700 fisherman with a 2005 90 etec. I also own a 2005 90 etec from my older boat both motors are 2005 and interested in mounting together on the new lund boat. Can anyone steer me in a direction to find out the process and expense of rigging them up?

 

[Huron Angler]

Re: Twin 90 etecs installation

Sounds like a good plan...as long as the transom has enough room

What's the hp rating on the hull? I'm guessing 140 max, so two 90s may be too heavy and too much thrust WOT.

If you do decide to go thru with this I'd recommend having a marina make sure you're set up for counter-rotating props to avoid possible issues with both spinning in sync.

Also may want to check out that transom wood and make sure it's up for the additional load...those etecs are 2-stroke(lighter than 4) so you may be fine in that regard.

Are they DFI Evinrudes? My dad bought a 2009 60hp DFI etec for his "little" boat and that thing is sweet. Quiet, powerful and starts flawlessly

Good luck!

 

[joatmon]

Re: Twin 90 etecs installation

the 05 lund fisherman 1700 beam is 93" and is all aluminum double rivetted and the present 90 Etec looks pretty small. I do believe that I have approx 4' of spread area to mount the engines on. But won't have the boat until the weekend.
The boat is rated for 150 horse and wondering if you put 2 90's on it does it actually double the horsepower?
I am not sure if there are DFI but they are direct oil injection.
Does meet all California emmisions.
What does DFI mean DIRECT FUEL INJECTION?
Your right they are great engines which is why I am thinking of doing this.

 

[Huron Angler]

Re: Twin 90 etecs installation

DFI is direct fuel injection. I believe that two 90s will not only equal but surpass one 180hp outboard(not that they exist) as far as thrust. The extra weight from having two of every part compensates for that to balance it somewhat as well.

I would recommend driving the boat with one 90 and see what ya think. My dad's got the 60hp Evindude etec DFI on a 17' aluminum boat(sea nymph) and it's plenty. She hops out of the hole in a blink and does 34-40 in small chop

I would imagine that you want the safety and redundancy of dual OB's more for offshore runs in the ocean more than for top speed?

 

[Knightgang]

Re: Twin 90 etecs installation

I would say that you probably loose about 15 horsepower from overall with twins. So instead of 180, you will probably actually see about 165. I would see if the motor you are mounting to port can be converted to counter rotating... That is the only real issue I see, provided your hull can handle the weight of both outboards...

 

[86 century]

Re: Twin 90 etecs installation

I was thinking of doing twin 115's from the 70's on an old jet boat hull. (mostly because I have them) Just as a toy so if you get it done I would like to see it

 

[tashasdaddy]

Re: Twin 90 etecs installation

this is what the coast guard says about overpowering boats.

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.

iboats recommends that you stay within the HP rating.

 

[ezmobee]

Re: Twin 90 etecs installation

I cannot imagine twin 90's on a 17' boat. I would think they would be way too heavy.