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Old 07-10-2012, 12:36   #1
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How heavy an outboard off the transom of a Pearson 30 ?

How heavy an outboard off the transom of a Pearson 30 ?

Have a 1973 Pearson 30 (atomic 4 needs to be pulled) ; how heavy an outboard can I hang off the back given how thin the fiberglass of the transom is ?
When I installed the OB bracket 10 years ago ( in fear of the A4 failing ) I fiberglassed in a backing plate and a 2 X 2 foot piece of fiberglassed plywood “front plate” on the outside of the transom. So the screws of the OB bracket go through the outside plate, the transom and then the backing plate. I still worry about 40 to 80 pounds of static outboard engine weight pounding on that transom and stressing the whole structure of the back of the boat.

(I'm working on the Atomic 4)
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Old 19-01-2013, 21:50   #2
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Re: How heavy an outboard off the transom of a Pearson 30 ?

HI! I would look at the designs of the Cape Dory 25's "The motor well" Or start thinking electric motor's.. Good luck and sailing too. Linda
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Old 19-01-2013, 22:23   #3
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Re: How heavy an outboard off the transom of a Pearson 30 ?

my neighbor put a 15hp 2 stroke on his p30 when his a-4 went bad. had it on for a couple of years. he finally rebuilt the a-4 but left the bracket on the stern. just in case....
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Old 19-01-2013, 23:06   #4
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Re: How heavy an outboard off the transom of a Pearson 30 ?

I don't know the boat, but jeez - I'd think that with the mounting reinforced like that you'd have no problem hanging less than 100lbs off the back...

If it was me, I'd go out there and just stand on the mount and just see if the transom flexes at all. If it doesn't, or if the flex is minimal, seems like you should be good to go.
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Old 20-01-2013, 00:14   #5
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Re: How heavy an outboard off the transom of a Pearson 30 ?

Your transom reinforcement sounds bulletproof.

I would find out what the bracket is rated to carry and stay within that except for very short trips in calm weather, which is when you really wouldn't need a very large motor anyway.
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Old 21-01-2013, 10:31   #6
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Re: How heavy an outboard off the transom of a Pearson 30 ?

Barrett, I've often wondered why sailboats 30' or less carried an inboard motor. If you really sail your boat, all you need is a 10-15 HP outboard to get you in and out of a harbor/anchorage or to motor on calm, windless days. It is far more practical than an inboard, less maintenance, less labor intensive and can be removed to be serviced. You have adequately reinforced your stern (which might not have been necessary) for the mounting and I can see no good reason to ever reinstall another inboard. You will defintely spend more time sailing, less time in harbor and have additional space for stowage. I often miss the simplicity of the 25 foot keelboat I sailed for almost 20 years and the minimal maintenance needed for it to run well. Buy a quality bracket with a polycarbonate mount (no maintenance) and you'll be one happy sailor. Good luck and good sailing.
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Old 21-01-2013, 10:45   #7
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Re: How heavy an outboard off the transom of a Pearson 30 ?

When I had similiar concerns I made a kicker that went from the mounting bolts back to the cockpit fiberglass. It stopped all movement. I think I used a pieces of angle aluminum.
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Old 21-01-2013, 10:55   #8
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Re: How heavy an outboard off the transom of a Pearson 30 ?

Surely the thrust for a larger outboard is considerably more than it's weight. For example, a 10hp outboard could easily be producing 300 lbs of thrust, a 15hp 450 lbs, and so on. This is acting on a lever arm maybe 2ft long? That's 900 lb/ft of torque on the mount.

So I think a better test would be to put the o/b in full forward, then full reverse, and check for excessive flexing of the transom.
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Old 21-01-2013, 13:24   #9
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Re: How heavy an outboard off the transom of a Pearson 30 ?

i once had an albin vega (27 feet) with an albin gas inboard. had many problems with it and found parts very expensive or even unobtainable. i pulled it out one day and put a 7.5 johnson sailmaster on a transom bracket. worked wonderfully. i cleaned up the former engine space and made it into a large storage area but mostly for a bladder water tank.

couple of years after we sold it we were sailing into bullock harbor in the berry islands (bahamas) when i saw a boat there that i instantly recognized by the outboard on the stern. the couple we sold it to had been living on it in the bahamas for the past year...
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Old 22-01-2013, 16:33   #10
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Re: How heavy an outboard off the transom of a Pearson 30 ?

I have a 60lb 5 hp 4 stroke Mercury on a Panther Bracket on my Bristol 27. No backing plate was installed. I've used it in heavy winds of say 18 knots/5 foot waves with no real problems. My bracket has a range of 14" and the engine has an extra long 25" shaft.

Also, the darn thing is like a tugboat in the slip. I can turn the outboard 0-180 degrees either direction and put the boat anywhere.

I wouldn't want the inboard back. It (the prop) used to cause my rudder to shake a bit also. Plus as a catamaran sailor for 15 years, I never had a motor on a boat before and don't like all that goes with it on an old boat with the leaks and smells etc.
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Old 24-01-2013, 01:01   #11
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Re: How heavy an outboard off the transom of a Pearson 30 ?

hello Barrett, sounds like you've got it nailed, my 26 glass cavalier which I've owned for 24 months now has a 8hp mounted to a rise and fall bracket bolted on the tranny.
When you get clear of things you just winch the outboard up its track drop in the lock bolt and it sits there just like a little kolah bear huggin its mum's back, motor wieghs in at 48kg/100pnd, glass would be around 8mm thick, no flex or movment, has coped well in a couple of gales
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Old 24-01-2013, 08:14   #12
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Re: How heavy an outboard off the transom of a Pearson 30 ?

Quote:
Originally Posted by rognvald View Post
Barrett, I've often wondered why sailboats 30' or less carried an inboard motor. If you really sail your boat, all you need is a 10-15 HP outboard to get you in and out of a harbor/anchorage or to motor on calm, windless days. It is far more practical than an inboard, less maintenance, less labor intensive and can be removed to be serviced. You have adequately reinforced your stern (which might not have been necessary) for the mounting and I can see no good reason to ever reinstall another inboard. You will defintely spend more time sailing, less time in harbor and have additional space for stowage. I often miss the simplicity of the 25 foot keelboat I sailed for almost 20 years and the minimal maintenance needed for it to run well. Buy a quality bracket with a polycarbonate mount (no maintenance) and you'll be one happy sailor. Good luck and good sailing.

Rognvald...You the Man!! I still to this date wonder why myself. I have the P303 or you can call it P30. Although I haven't had problems with the engine yet, I still wonder what do we do replace it or remove it! Cost's the same approx. However; would be nice to take it home for servicing and winterizing. I'm always jealous when I see the Dory 25's and the outboard motor well's in the sterns... but that's me! LOL Linda
Anyone have any pic's please share them. Thank's
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Old 24-01-2013, 09:04   #13
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Re: How heavy an outboard off the transom of a Pearson 30 ?

The other consideration of putting an outboard on a 30 foot boat is that when it starts pitching in a chop there is no long shaft that will be long enough to keep the prop in the water. So really, it will only be useful in relatively calm to moderate conditions which may not be a good thing when it is rough out and you are in a situation where sail power is not an option.
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Old 24-01-2013, 09:06   #14
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Re: How heavy an outboard off the transom of a Pearson 30 ?

I have a 5hp 2 stroke nissan and love it. I did not want the smelly and expensive engine inside. I get the extra space inside and have a much easier to maintain and work on engine hanging on the back.

the po reinforced it a bit, but I will be redoing it. I'm going to glass in a 1/2 in of ply on the inside covering the entire rear transom.
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Old 24-01-2013, 12:43   #15
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Re: How heavy an outboard off the transom of a Pearson 30 ?

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The other consideration of putting an outboard on a 30 foot boat is that when it starts pitching in a chop there is no long shaft that will be long enough to keep the prop in the water. So really, it will only be useful in relatively calm to moderate conditions which may not be a good thing when it is rough out and you are in a situation where sail power is not an option.
I have an outboard (5hp) on my Bristol 27 with an extra long 25" shaft on a bracket with 14" of movement. All the way down, the prop is just above where the inboard prop would have been. Only problem I've had so far with the prop coming out of the water was when I forgot to lower the bracket.

If motored in 5-6 foot choppy bay waves before with no real problem except for my lack of speed with such a small engine on a 6600lb boat. In the future though, I plan to sail as close as I can get to the creek before motoring because it's usually faster (AND) I own a SAILBOAT which is another reason I don't have a 15hp motor attached to the stern.
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