Twin o/b's in smaller HP

Mark42

Fleet Admiral
Joined
Oct 8, 2003
Messages
9,334
I like the idea of having twin outboards from the redundancy point of view (one has problem, the other gets you home). In a twin o/b setup, when turning what keeps the outside motor from ventilating the prop as the boat leans and the outside chine lifts in the water? Is this condition worse in large or small boats?
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: Twin o/b's in smaller HP

The condition of the prop and the technology of the given prop will keep it hooked up. Just like a single. Not really any different.<br /><br />BTW -- why do you want twins? No room for 3?
 

joblo33

Chief Petty Officer
Joined
Jan 19, 2005
Messages
501
Re: Twin o/b's in smaller HP

I saw someone with three Johnson 15's on a 14' but it looked like he was constantly grabbing different tillers to keep them throttled up. He was flying tho. He docked beside me at Surge Narrows and I had to meet him. He said he just had them sitting around and he welded up a linkage. I should do that with 3 or 4 of my 9.8 Mercs. Two short shafts on the outside and two long in the middle would be sweet, I just need to find a boat with a wide enough transom. :p The Merc's have a tightener on the end of the throttle arm too so I wouldn't have to fiddle with the tillers.
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: Twin o/b's in smaller HP

Now we're talking! A whole row of 'em!
 

RobG

Petty Officer 2nd Class
Joined
Nov 29, 2004
Messages
101
Re: Twin o/b's in smaller HP

With a twin setup, does one prop spin clockwise and the other counterclockwise? Would it cause any problems having 2 spin the same way?<br /><br />Rob
 

Mark42

Fleet Admiral
Joined
Oct 8, 2003
Messages
9,334
Re: Twin o/b's in smaller HP

I know that bigger motors often have the reverse rotation option for twin setups. But I have not seen it for smaller motors like the twin cylinder models. I suppose the linkage could be modified so one runs in reverse gear, but there is still the problem of finding a reverse rotation prop for small motors.<br /><br />Dhadley, the recient unfortunate demise of my 40 and the expense of a new power head just makes me think of safer setups. Three 15 hp sounds good to me!
 

swist

Senior Chief Petty Officer
Joined
Jul 1, 2004
Messages
678
Re: Twin o/b's in smaller HP

The common wisdom these days seems to be that the expense and extra weight/fuel cost of twins is hard to justify in a recreational vessel. Someone here once said that 85% of all failures were fuel related (including just plain ruuning out!) at which point both engines would be affected. Modern outboards when well maintained are pretty reliable and you are paying a real price for turning 97% reliability into 99%.<br /><br />Obviously this not apply if you are runnig clunkers!
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: Twin o/b's in smaller HP

Mark, sorry to hear about your 40 -- bummer. Are we rebuilding or looking for something else?
 
Top