HP Required for Southwind

[mcagnew]

I have a 1973 GymCraft Southwind its 18.5' long This is a picture of it when my dad had it back in the 70s. I ended up buying the boat back from the guy he sold it to and gave it to me as a gift..I remember sitting in his lap driving it back in the 84 time frame. <br /><br />

<br /><br />The boat currently has the original 1973 Chrysler 130HP Outboard on it (shown in the picture), but is missing the lower end..so we are deciding to replace it. I want to go with a mercury outboard. The boat plate says the boat is rated to 135HP. I talked to Mercury and they told me that the chrysler motor that is on the boat now is equivalent to about a 100HP today because of the difference in the way the HP was rated (flywheel vs prop now). So what HP level do you think is adequate. I was looking at the Mercury 125 Classic. Any thoughts??

 

[Kiekhaeferscurse]

Re: HP Required for Southwind

Would be kewl neat to keep the Chrysler on it, I dont think Solictation is alloed on here & and I sure dont want to get in trouble, but I happen to have the gear case for that puppy.<br /><br />100/125 hp Merc (2stroke) would be about right, wieght is a concern on that ship.<br /> Nice looking boat

 

[mcagnew]

Re: HP Required for Southwind

I think the chrysler would look good on there too...I was even thinking of rebuilding it. <br />I don't think that solicitation...I have everything from the driveshaft up but nothing else. So I need lower end...plus I will need a prop.<br />I am 26 years old and everyone loves these new 25+' boats nowadays...but I still love the old stuff. I guess it goes along with my car seen here<br /> Race Car <br /><br /><br />How much would you want for it and where are you located. My dads friend had taken it in to get rebuilt and never picked up so my dad went down there about 10-15 years later and naturally it wasn't there anymore.

 

[Kiekhaeferscurse]

Re: HP Required for Southwind

Wow thats quite a car you have there....least we no speed isnt a problem for you....lol<br />I do have a Gearcase if you want it. 400 bucks canuck money should cover it, I'll crate it, if you pay for shipping.<br />I had a 67 Chevelle with a 396 when I wasa a youngin, but it would have been no match for that Fire Briether you got there.

 

[mcagnew]

Re: HP Required for Southwind

Is it rebuilt ready to go..have pictures?? you can email them to me at michaelagnew@msn.com

 

[Kiekhaeferscurse]

Re: HP Required for Southwind

It's not rebuild, its from a trade in (powerhead blown up) will take some pics on Monday & email them to you if thats okay? engines at the shop<br />If yuo decide to go for it, I will Vac & psi test the unit for you, and put in new gear oil.

 

[mcagnew]

Re: HP Required for Southwind

Talk to my dad...he wants to go with a new motor in order to start from scratch. I think we will be going with the Mercury 125 Classic as he doesn't think the transom will hold the 135 V6

 

[Kiekhaeferscurse]

Re: HP Required for Southwind

okay, good choice for power strong dependable and parts are cheaper.<br />Guess the only thing you might want to consider & this is only if your gonna be tubing, is the fact that the 125 is an awfull runner at the 1800 to 2400 rpm range, other than that its a great motor.<br />Cheers

 

[mcagnew]

Re: HP Required for Southwind

why do you consider it to be an awful runner at that rpm range. Also what about the 2-cylinder firing at below 1800 or something I read about...is that good for a motor?..and is it alternating (i.e. the two cylinders that aren't firing switch in order to eliminate fuel-air build up in cylinders..(sort of like an MSD box with a revlimiter on a race car)) <br /><br />He also made the point that if the chrysler broke down at the lake, I would probably be boatless the rest of the week since the parts aren't as available as a newer mercury

 

[Chris1956]

Re: HP Required for Southwind

mcagnew, I have a speedboat similar to yours, only it is 16 feet long. I have a Merc 1500 Tower of power (straight six cylinder)on it. The motor is only 300 pounds. I get great performance out of it.<br /><br />The V-6 motors tend to weigh in at 450 pounds or so. I would think this is too heavy for comfort, on that boat. I would stick with a 2 cycle motor for the same reason. OMC has made 115 HP V-4 motors for years. One of these may good for you. You could also find a used 115-140 HP inline six Merc.

 

[Kiekhaeferscurse]

Re: HP Required for Southwind

Hi mcagnew<br />as you know the 4 cyl has 4 carbs, on the bottom 2 merc removed the idle circuit, so what happens is at an idle (up to about 1800) rpm the bottom cylinders 3&4 recieve no fuel flow hence they dont fire (you dont even notice this) as the rpm increases Bernulies rule comes into effect and the off idle (or midrange circuits) in all 4 carbs begin to flow fuel, this is where the engine gets a stutter(some call it a miss)as the bottom 2 carbs transistion into full fuel flow. Nothing fancy about the system. If you can borrow a manual for the motor you will be able to trace the fuel flow diagrams and see exactly how it works.<br /><br />your dad is quite right, the merc is going to be quicker to fix (and a lot less prone to breakage)I never thought that Old Chrysler might have a prestolite ignition system and they were nothing but grief.<br /><br />Good luck keep us posted.

 

[mcagnew]

Re: HP Required for Southwind

interesting...I will keep that inmind They have a boat show here in Los Angeles starting Saturday so I will talk to mercury about that

 

[mcagnew]

Re: HP Required for Southwind

I am wondering what if we added the idel circuit back to the lower carburetors?

 

[Kiekhaeferscurse]

Re: HP Required for Southwind

You wouldnt want to do that, as it would void a warranty on a new engine.<br />It would also require purchasing another set of carbs and removing the injection system that merc install (this is used to overcome bog when you hit it)<br />All in all it just wouldnt be a great idea.<br />This rpm range is very small and you may not even notice it.Search this forum for opinions from other people on the subject.<br />Have fun at the boat show.

 

[bluewater19]

Re: HP Required for Southwind

I love my 1996 125 2+2.<br />I think your boat will fly with one of those on there.<br />Good luck!