Dual motor question

[what200]

I have a question concerning dual setups. The advantages are somewhat obvious. However, I was wondering about the problems that come with dual motors. Does one motor have to rotate in the other direction? Is cavatation a bigger problem, and how is handling normally affected? Being new to outboards I will appreciate as much info I can get.

 

[mikec]

Re: Dual motor question

You will have one engine that is counter rotating. From what Ive experienced, dual outboards are not as manuverable in a small area as twin inboards because the screws are set so far back on outboards, where on inboards they are under the boat, giving you a better pivot point. (when you want to put one in forward and the other in reverse for turning)<br /><br />Cavitation is not any more an issue than with a single setup from what Ive seen.

 

[Walter]

Re: Dual motor question

Fuel consumption is higher with twin outboards...two 75 hp will burn considerably more than a single 150. Some years ago, "Boating" magazine wrote an interesting article on the subject of twins vs. single. As I recall...the biggest advantage of twins is the piece of mind one has when boating in big water with two engines hanging on the transom vs. one. Other than that...it seems to me the single beat the twins in nearly every other aspect (hole shot, top speed, maneuverability, noise, original cost, maintenance cost etc.)<br /><br />Walt

 

[Walter]

Re: Dual motor question

Before this topic gets lost...I was hoping to hear other's opinions on this subject. <br /><br />Fone_Man, JB, Clanton, ODDD1, Dunk... What do you guys think?<br /><br />Walt

 

[fone_man]

Re: Dual motor question

Put Twin Screw Mercrusiers in it!!!!!!!<br /><br />Hows that Walt... they were giving up & down the road last night because I do not like synthetic floats... Brass,... Baby. But opinions are like elbows, eevrybody's got two of 'em.<br /><br />

<br /><br />------------------<br />"Keep It Between The Bouys" & "Good Luck"!!!<br /><br />fone_man

 

[JB]

Re: Dual motor question

Ahoy, What. Seasoned boaters use one main engine and an aux. The main engine will be 50 to 100% of rating and the aux 10 to 25% of rating.<br /><br />Example: a Boston Whaler Outrage 18 will have a 150hp main plant and a 25hp aux. They will use the aux for trolling and gunkholing just to keep it exercised, but its main function is backup.<br /><br />Red sky at night. . . <br />JB

 

[clanton]

Re: Dual motor question

I think it depends on the boat, but where twins realy shine is when you are 50 offshore and one of them will not start. I dont have boat, but I like to pile on the horsepower.

 

[Walter]

Re: Dual motor question

Basically...I was curious to know your opinions whether having twin engines of equal horsepower to a larger single has advantages... other than the obvious fact that two power plants are less likely to fail at the same time as one. That is, of course, unless they share the same fuel supply!!!<br /><br />Oh yeah....on a totally unrelated note...my boat is coming home from the upholsterer's tomorrow!!! Yeee-hawww!<br />You guys gotta see this thing...she's looking really great! She may even go for her first sea trial this weekend...well, that's the first since she's been rebuilt! Gee Fone_Man...do you think she can handle all the power of that fresh 350???? I can't wait to find out!!!<br /><br />Ahhh yes...one last thing: Thanks for the great info you've all provide to the folks posting questions. I think I've just surpassed my 200th post...but that's nothing compared to what other's have contributed. This danged site has become an obsession with me...and IT'S ALL YOUR FAULT!!!!!!!! <br /><br />Walt

 

[what200]

Re: Dual motor question

I appeciate the advice JB. I think a small spare makes the most sense. After all two motors are less likely to screw at same time but one of the two is more likely to screw at any given time. But I was also wondering what problems arise in a dual setup if both motors rotate the same direction?

 

[hondon]

Re: Dual motor question

You will experience considerable steering torque that you will likely not be able to adjust out with the trim tabs. If these are small enough motors you may be able to live with this. Seen alot of people do it.If you can't there are steering systems that help a great deal.B.T.W. I have yet to see a recreational twin engine set up their fuel delivery properly. Twins won't do you any good if all those carbs are water fouled.I like the idea of twins ,but run them on separate fuel sources if you can,separate fuel pickups with a water filter on each,if you can.