advantages of twin o/b?

[spartaboat]

I'm looking at a Craigslist ad for an older Mako with twin 75 horse johnsons. Is there an advanage to twin o/b's? I would think that it's 2x the maintenance (disadvantage). Do twins handle better, turn better or.....?

 

[JoLin]

Re: advantages of twin o/b?

Yes, it's twice the maintenance, but in this case I assume the owner wanted reliability and failsafe when running offshore. If you're bay/lake boating (I don't mean the Great Lakes), then a single, large outboard (maybe with a small kicker/auxiliary motor) is usually the most cost-effective way to go.

My .02

 

[Philster]

Re: advantages of twin o/b?

Redundancy is the main advantage. Sometimes, it is also the only way to get sufficient power.

In smaller HP applications, it really is about redundancy.

 

[Fireman431]

Re: advantages of twin o/b?

Also add that twin engines make for much easier maneuverability, especially in close quarters. Although it is twice the maintenance, O/B expenses are low if run properly. Also, the engines work a little less for the given weight of the boat, as long as they are sized correctly.

 

[metriccrescentwrench]

Re: advantages of twin o/b?

Also, the engines work a little less for the given weight of the boat, as long as they are sized correctly.

I believe that's incorrect, and here's why... You have twice as much lower unit surface area in the water, adding a significant amount of drag. Twin 75's are going to be slower than a single 150 for that reason, or at a given speed will burn more fuel because of the increased power required to overcome the extra drag.

 

[Home Cookin']

Re: advantages of twin o/b?

plus for efficiency you can run just one for slow applications--trolling, cruising, interminable no wake zones, etc. Just pull the dead one up.
However, you typically don't see twins less than 150 each any more. Must be an old rig. Back in the day, when they didn't make big motors much, you'd see twin 20's and 40's. I might rather have a newer 150 than two old 75's.

As far a a back up for mechanical problems, it makes sense only if you go a long distance off shore, or boat in remote places, but not in an area served by a towing service.

 

[dingbat]

Re: advantages of twin o/b?

A large precentage of "breakdowns" are fuel related. Connecting twins to a single fuel source doesn't buy you much. Twin motor, twin fuels sources. Otherwise I'll take a new, single OB in a heart beat.

 

[Philster]

Re: advantages of twin o/b?

When you get into 30' + offshore pounders, you are looking at twin power whether you like it or not (unless you scope out a new Seven Marine 557 HP O/B).

 

[Fireman431]

Re: advantages of twin o/b?

I believe that's incorrect, and here's why... You have twice as much lower unit surface area in the water, adding a significant amount of drag. Twin 75's are going to be slower than a single 150 for that reason, or at a given speed will burn more fuel because of the increased power required to overcome the extra drag.

For 2 75's vs. a single 150, you're correct. For one that's sized correctly (as I stated). I am correct. Running twin 100's or 125's, the engines would work less, easily compensating for the minimal drag created by the second lower unit. There are plenty of sites which prove this, giving the fuel readings, usage, drag coefficients, etc.

 

[spartaboat]

Re: advantages of twin o/b?

this is the boat I'm referring to. I suppose i'd be easiest to just call him & ask about it, but I wanted your opinions on it. Thanks and tell me more of what you think. I'm leaning towards a 1987 Pursuit for $2K more. I'm moving onto Lake Erie in a couple weeks.

http://nmi.craigslist.org/boa/2911435602.html