Repowering a San Juan 28 with outboard?

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Sep 25, 2008
77
Macgregor 25 Naples, Fl.
I am looking at a 1979 model San Juan 28 that doesn't have any power (Atomic 4). This boat has the classic wine glass transom and a center boarding ladder. I am asking for advice/views on repowering this boat with an outboard engine instead of replacing the Atomic 4 that it was designed with or the Universal Diesel. The displacement is 6000 lbs. / 3200 lbs balast / 4'6" draft.
 

BobM

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Jun 10, 2004
3,269
S2 9.2A Winthrop, MA
2c

I tried to include a photo to aid the discussion. I'm not sure if it attached.

http://www.moyermarine.com/ is a source for A4 parts...even updated replacement engines for about $4500. I wouldn't fear keeping the A4 from a reliability perspective.

It is probably doable to mount an outboard on the stern offset, to allow ladder use. You will just need an extra long (25") shaft and an outboard bracket with a lot of downward travel and mount it as low as possible. I'd opt for electric start for sure, as it will be a pain to start otherwise.

Garelick is a good source for mounts and here is a link to a comparison of what they have available. http://www.garelick.com/obmbtable.html

71039: H.P. Rating: Over 7 1/2 to 12 Motor Weight Not to Exceed: 82 lbs. Vertical Travel*: 14 1/4" (36cm) Mtg. Pad: Poly Mounting Board Dimensions W x H x T: 11 1/2" x 10 3/4" x 2" (29 x 27 x 5cm) Mounting Bracket Dimension W x H: 7 5/8" x 7 7/8" (19 x 20cm)

It seems that 14 inches is the max vertical travel they have, but be careful because vertical travel in the downward direction (E) is what is likely most important to you (max seems to be about 5.5 inches).

I suggest you take some measurements based on the outboard bracket you identify as well as the dimensions of a long shaft outboard and then look at the boat again to see if it is feasible. I searched for a 28 with an outboard mounted, but didn't find one readily.

Good luck,

BobM
 

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Jim

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May 21, 2007
775
Catalina 36 MK II NJ
Mac, good question and two good reply posts. I am an SJ fan but re-power an old boat is not my cup of tea. You'll never get your money back out of the boat. If you have the time to do the job your self, I estimate the cost of a diesel at 10 - 12 large. If you get the yard to do it, more like 15 to 20 large.

I am not sure you can't buy a nice Catalina / Hunter 28 or 30 in the early 1980 for the same investment.

That said, if you love the boat, maybe you can justify the price better than I!

I do believe an outboard would be too much trouble. The boat is too big.

I would not re-power anything except my lawn mower with a gas engine.
 
Oct 2, 2006
1,517
Jboat J24 commack
And outboard is just not able to stay in the water in bad conditions on large boats


Even on my J24 with a longshaft and good mount the motor is JUST deep enough and will still come out of the water if it is really rough
 
Dec 1, 1999
2,391
Hunter 28.5 Chesapeake Bay
My comments fall into two bins: esthetics and practicality. To me, all the San Juans are very good looking boats. Hanging an OB on such a boat will really detract from its appearance, yet I know that is a much lesser cost solution to your problem. But a big part of boat ownership is really liking how your boat looks (and performs, of course). I also think that while an OB would certainly power this size/displacement boat, you are really at the limits of performance under power with an OB. While an appropriately sized OB will certainly be able to push this boat in most wind/wave conditions, you will eventually find yourself with a cavitating prop in some nasty conditions. That will not be a fun time. If you really like this boat and plan to keep and cruise for a long while, I think rebuilding the A-4 (or having Moyer do it for you), or installing a used rebuilt diesel will be a much better, albeit more expensive, option. Good luck with this nice looking boat!
 
Jun 3, 2004
890
Hunter 34 Toronto, Ontario Canada
You might try this side of the border

for Atomic 4's or parts. There are lots of them up here- C&C used them for years.

The 80 cent $ helps also.

This publication often has motors and or parts.
http://www.boatforsale.net/

I agree withthe comments about OB's cavitating- I have a Johnson 6 with long shaft on our SJ24 and it is a problem in bigger waves
 

higgs

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Aug 24, 2005
3,704
Nassau 34 Olcott, NY
It is not clear to me if the A4 is in the boat or is gone. I would scrounge around for an engine to rebuild. Look in classifieds in Boat US, Soundings and those type of publication. Also ebay may be a source. Moyer is a great guy to deal with and more than fair.

The A4 is very easy to work on for any reasonable handy person. I rebuilt one back in '92. The machine shop reassembled the short block for only $75 - the toughest part of the job. I did the job for under a grand.
 

higgs

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Aug 24, 2005
3,704
Nassau 34 Olcott, NY
Another thought - down around where you are there has got to be a lot of hurricane boats that were totaled. Also check out sailorman.com as they deal in used parts.

How's the weather in Naples right now. I rented a conco down there for next month. I have never been there and am looking to escape the foot of snow on the ground right now.
 

larryw

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Jun 9, 2004
395
Beneteau OC400 Long Beach, CA
All good advice, and not sure about FL, but in CA many marinas won't let you in unless the boat is able to leave the slip and exit the marina under it own power, in the DESIGNED AND BUILT configuration, which means if it had an inboard engine, hanging an outboard on the transom is not an option, besides which, will ruin the boat's lines. I don't mean to sound elitist, but if you can't afford to keep the boat in its orignial form, perhaps you can't afford a boat and should just give it up. Donate it to a charity, perhaps, or auction it off, as-is where-is.
 
Feb 6, 1998
11,701
Canadian Sailcraft 36T Casco Bay, ME
I am looking at a 1979 model San Juan 28 that doesn't have any power (Atomic 4).
You will hear this a million times about boats but here it is once again. There are NO good deals buying inexpensive boats that need money thrown at them! You will lose out every time over a comparable boat in tip top condition. It's a spend it now or spend it over time proposition except the "needs work" boat will always cost far more in the long run.

Find yourself a good clean boat in sail away condition and it will cost you MUCH less in the long run.. If that boat needs a motor how much more does it need? Wet decks? Keel re-set? Standing rigging? Sails? On and on and on and on...

As far as I'm concerned a boat needing a re-power, in that price range, should be given away not sold. Even for free it's probably no deal.. There are plenty of boats out there so I'd keep looking..
 

Jim

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May 21, 2007
775
Catalina 36 MK II NJ
I agree with Sail M except, if you love the boat...

I mean really love the boat. The SJ-28 is a limited numbers but you should be able to get one with a working engine.

I have not found a boat I love that much!
 

Benny

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Sep 27, 2008
1,149
Hunter 320 Tampa, FL
I'm with Warren. To rebuild an atomic 4 and transmission is probably the most inexpensive alternative. You would require at minimum a 9.9 HP outboard engine. Since new engines available are 4 stroke for that size you are looking at 110 lbs which means that for practicality you would probably want a fix mount as this is not something you want to raise and lower frequently. Outboard engines of this size run about $3,200 plus controls and the installation of a mount you would be looking at $3,500 to $3,800. Because of the way your stern is configured you would need a long shaft model to try and keep that prop in the water and reduce cavitation. The Atomic 4 is a very simple engine and there are plenty of sources for parts. It is a powerful engine that will propel your boat under various conditions. The SJ 28 has beatiful lines and an outboard would just ruin it.
 

Ross

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Jun 15, 2004
14,693
Islander/Wayfairer 30 sail number 25 Perryville,Md.
If you have a sound hull with a new engine and new standing and running rigging and all of the other systems are in good working condition................Don't you have a new boat? Where can you purchase a new boat for the price of an engine and the rigging?
 

Jim

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May 21, 2007
775
Catalina 36 MK II NJ
Ross, the answer is NO!!!!!!

Not at all!

How about the rudder post, the steering system, the chainplates, what is the wood work like, is there water in the core (I think so), how are the keel botls, what do the sail look like, do the windows leak....

I new boat, should, and I say should be, perfect!
 

Ross

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Jun 15, 2004
14,693
Islander/Wayfairer 30 sail number 25 Perryville,Md.
Not at all!

How about the rudder post, the steering system, the chainplates, what is the wood work like, is there water in the core (I think so), how are the keel botls, what do the sail look like, do the windows leak....

I new boat, should, and I say should be, perfect!
I used a sound hull as a basis for mounting the engine and rigging. Is this your discription of a sound hull?
 

Jim

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May 21, 2007
775
Catalina 36 MK II NJ
I don't think so? The hull to me is the product that comes out of the mold. I see what you are thinking, but you would have to admit that there is no way a boat doesn't weather unless you keep it inside all the time in a climate control environment.
 

Ross

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Jun 15, 2004
14,693
Islander/Wayfairer 30 sail number 25 Perryville,Md.
Mainesail, Have you ever seen a perfect new boat? That you could afford?
 
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