Twins on a small boat

[AJ168]

Just today while looking at engines for a repower, my friend made me realize that I can get two brand new Mercury 25 hp's for my boat for about half of what I'd pay for a 50 hp. I realize that I'd have to spend a lot on rigging but is this an idea that I should look into? The boat is a 1989 aluminum Fisher. The motor that was on it was a 55 hp. Will the extra weight of the two motors be too much. I don't know the maximum horsepower rated for the boat because I can't seem to find the capacity plate. I've covered every inch of the boat and haven't found it.

 

[steve reuter]

Re: Twins on a small boat

i dont know about weight or horsepower but... twin 25 would look cool since ive never seen it..goodluck and take pictures and post em

 

[ZmOz]

Re: Twins on a small boat

You can find the rated HP using the formula length x width x 2 - 90. You'll get a ridiculous number not really related to the boat's ability to handle power, but that's how they figure what's on the capacity plate. If it has a 55hp now 2 25s should be fine, as long as it can handle the weight. It would definately look cool, and you'd have a backup should one break down.

 

[TheViking]

Re: Twins on a small boat

I'd be concerned with the added weight. You also would need to adapt the steering to keep them in sync and purchase a control unit(and harness)capable of running dual motors. Plus the added fuel lines, etc. Somehow I think you'd wind up spending close to the same in the end.

 

[JasonJ]

Re: Twins on a small boat

It is doubtful that the weight will be an issue. It will be a tad slower that if there was a single 50 on there, and fuel economy is an unknown, but coolness factor and peace of mind factor would be increased. I know a guy with a 19 foot aluminum Starcraft with twin 35s on it. He seems to like it (it was given to him in this configuration).<br /><br />You just need to make sure there is room on the transom for both, and realize that, depending on deadrise, you may have to mount them higher on the transom, and that the transom may have to be modified to accomplish this. Also, odds are, they will both be running the same direction (as opposed to counter rotating), and that will cause interesting handling as well. If it were me, I'd go with a single 50 and a kicker. Good luck though, and post pics...

 

[JB]

Re: Twins on a small boat

In the Bahamas back in the 80s I saw a lot of small boats rigged with twins. A couple of favorites were Boston Whaler 13s with two 15s and Boston Whaler 16/17s with twin 50s.<br /><br />They handled like barges and squatted a lot at low speeds, but they always got back from the banks and flats. Losing power in the Gulf Stream is a serious issue and a kicker is spitting into the wind if you have to go south.<br /><br />I think it was only the security factor that inspired those arrangements, plus the fact that a single 15 can plane a BW 13 and a single 50 can plane a BW 17.<br /><br />The only excuses I can see are security in dangerous waters and maybe chicks dig twins.

 

[QC]

Re: Twins on a small boat

Originally posted by JB:<br /> maybe chicks dig twins.

When I first saw this topic I thought it WAS about chicks . . .

 

[BoatBuoy]

Re: Twins on a small boat

The Johnson Twins, from another forum <br /><br />

 

[CATransplant]

Re: Twins on a small boat

Back in the late 50s, when a 50 was the biggest motor you could buy, a lot of folks ran two 35 hp outboards. It looked really cool and worked really well.<br /><br />But, oh, lord, the fuel consumption!

 

[Silvertip]

Re: Twins on a small boat

But in the 50's fuel was 19 cents a gallon.

 

[solidwaste75]

Re: Twins on a small boat

how much did you get paid an hour though?

 

[AJ168]

Re: Twins on a small boat

Right now, my biggest concern with it is that the props won't be counterrotating. How poor will handling be?

 

[BF]

Re: Twins on a small boat

A guy in my neighbourhood had a 16' aluminum with twin 35's. They were remote steering with dual throttle controls. Very cool. <br /><br />I have a 16' aluminum (rated for 35 hp) that I used to power with a 15 hp evinrude (tiller). When I wanted more HP, I was greatly intrigued by the possibility of putting another 15 hp on it and running twins. I have seen twin tillers run around a lake once or twice in my lifetime, but I've never seen how they were rigged. It's entirely possible they weren't rigged together at all... just driven independently by a guy with busy hands. <br /><br />I posted a Q on this forum about rigging twin tillers... how to link them to steer together (which I could imagine with some kind of tie rod thing to connect the existing steering holes), whether a kit was available etc. also whether there was a way (via cable?) to link the throttles together so they'd both function by twisting one grip.... <br /><br />Nobody posted with any experience or encouraging words... I ended up buying an old 25 hp.... but it doesn't idle down nearly as nice as my 15, so I end up sticking my 6 hp on for a trolling motor. Upshot is that the 25 hp with a 6 hp trolling motor is probably about the same weight wise as twin 15's... and not nearly as cool

 

[Silvertip]

Re: Twins on a small boat

Don't know where you are buying engines, but my source shows a new Merc 25 HP at $2399 US. Thats $4798. That same source shows a Merc 50 HP Remote with Titlt & Trim for $3799. Twin 25's just doesn't seem like a cost effective installation.

 

[AJ168]

Re: Twins on a small boat

Yea the Mercs are that much but I get a pretty nice discount on that. (depending on the product sometimes more than half.) The place that I'm buying from doesn't carry anything larger than a 25.

 

[CATransplant]

Re: Twins on a small boat

That's true, but what about classic boats and motors? A couple of 25 or 35hp classic outboards won't cost all that much, and would look really cool on a matching boat.

 

[HeadHunt]

Re: Twins on a small boat

They would have to be counter rotating, correct me if I am wrong.<br /><br />HeadHunt

 

[AJ168]

Re: Twins on a small boat

That's exactly what I'm worried about HeadHunt. I want to know if anyone has had twin outboards that weren't counter rotating and how the handling was.

 

[ZmOz]

Re: Twins on a small boat

They don't HAVE to be counter rotating, though I'm sure it's better. I have no idea how it would handle with both turning the same way. Maybe you could run one in reverse?

 

[AJ168]

Re: Twins on a small boat

Isn't the gearing different in reverse vs. forward?