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View Full Version : Outboard motor mounting on yachts?



Banjo
08-10-2003, 08:58 AM
G'day all,

I have been weighing up the pros and cons of outboard mounting on my yacht. The boat is in the early stages of construction. The design shows a cutout with well for an outboard of around 6 - 8 hp. She is just under 18 feet o/a with 7 foot 4 inch beam.
I am also considering using a transom bracket instead but have never had much to do with them or spoken to other yacht owners about them, do they like them or would they prefer the motor in a well etc....

What's the consensus from you knowlegable folk out there?

bret
08-10-2003, 09:16 AM
Hey Banjo,
I helped my Dad install the mount for a outboard fishing motor on his runabout. The one we used for the most part works pretty well. A tiller/throttle extention is a must as its a fair reach down to the stock one. My only gripe would be that when you want to raise the motor it's a pain to hang over the stern, work the braket mechanism, and lift. At least for me. I recall doing this (it was my job) back in the days befor I became fat, weak, and slothenly and it wasn't very easy, These days it might be near impossible.

tnert
08-10-2003, 09:33 AM
From an aesthetic point of view, having the motor in a well is certainly the better option. But if construction or operational difficulties are a concern, well, it's your boat. smile.gif Personally, I'm reluctant to mount an outboard on my Lightning, but i'm afraid it will be necessary.

Gresham CA
08-10-2003, 05:28 PM
Mark,

The advantage to mounting your outboard in a well is that if you are offshore or in any kind of swell then your prop stays in the water.

tnert,

I use to race Lightnings with my father and unless you are in a tidal situation you wont need an outboard. They will move with a whisper of a breeze.

Chris.
08-10-2003, 06:45 PM
I have an outboard well in my recently acquired 22 sq metre. Though the boat is 41' long, I doubt if the cockpit is any bigger than yours will be (she is only 6' beam) and when NOT sailing the sharing of a smallish cockpit with a noisy smelly outboard is not one of life's pleasures. And when sailing, the bloody thing just gets in the way, sheets catch on it and water slops over the top and down your leg when on starboard tack.
As you might have gathered I am not a fan of this particular well, and I will in fact be planking the opening over next time she is out if the water.
I will instead replace it with either a removeable side or stern mount bracket, as I rarely use the motor. We sail on and off the mooring easily (Mosman Bay Sydney Harbour).
Unless you want to use your boat for fishing as well as sailing I would say skip the outboard and soend the money elsewhere.
Cheers,
Chris.

bainbridgeisland
08-10-2003, 07:48 PM
If you choose an outboard bracket, be sure it is strong enough.

More than 20 years ago, I worked for a Naval Architecture firm that gave expert testimony on a death caused by an outboard motor bracket that broke. It was a very sad story. The builder had designed the bracket himself, made from angle iron, and bolted it to the transom of a small powerboat. He did a reasonably good job and the bracket gave good service for many years. To maintain it the owner repainted the bracket to the point where the stamped horsepower capacity was hard to read.

The boat was sold to a new owner who replaced the engine with a more powerful one, not realizing the limits stamped on the bracket. Underway on a rough day, one side of the bracket failed, causing the motor to rotate. This caused the boat to roll, pitching one of the passengers into the water. Before the helmsman could recover, the boat spun a circle and ran over the passenger.

The builder was the guy at risk on the lawsuit. Though I am in no way a lawyer, the builder shoulders broad responsibilities unless a Licensed Engineer is involved in which case both the builder and the engineer are the targets. My recollection is that the case drove the builder out of business.

My point on bringing this up is not to keep you from using outboard brackets. I use them all the time. It is just that as builders, we have certain responsibilities we cannot dodge. Being sure the bracket is strong enough and the boat is properly marked as to engine capacity is one of those responsibilities.

Jeff Robinson
08-10-2003, 07:52 PM
My boat (Golant Gaffer) is designed for an inboard but I put a bracket on instead. The 4 hp ob works fine for poddling off and on the mooring, although we tend to sail off and on more than motor. In anything more than a chop, the propellor does spend more time out of the water than in. It is a pain in the back to lift it on and off the bracket, as we take it home for security. We are quite happy with the arrangements overall though, as it saved us a heap of money and she still sails well. We put more lead in the keel than the design weight, and beefed up the transom/planking joint.

We usually leave the motor at home but will probably lock it on to the boat for summer to avoid the lifting.

JR

JimD
08-10-2003, 11:28 PM
A timely thread for me as just today I made a transom bracket out of plywood. Its only going to hold a 65# thrust electric trolling motor for our 15 foot daysailer, but if it breaks I'll sue myself bigtime :D

Banjo
08-11-2003, 07:49 AM
Thanks people for your input, it looks like a tie so far. smile.gif

Recently I observed a fella setting up his (wash my mouth out) fiberglass trailor sailor for a bit a day sail. He had a mate with him and it seemed to take forever to get it launched. (Maybe I was making them nervous watching them?) In fact just after getting it in the water the wind picked up from the south building up a 2-3 foot chop just past the breakwater near the boat ramp. They fired up the outboard which looked to be around 6-8 hp and was mounted on a stern bracket. The motor pushed the boat well in the calm water but once past the shelter of the rocks they hit the chop head on, I noticed that each time to boat crested a wave and dropped her bows that the prop would lift out of the water much to the screeming protestations of the poor outboard motor. :eek:

I will be launching my boat at the very same boat ramp that I mentioned above, seeing this situation recently was very timely indeed. I would prefer my prop to stay in the water and maintain drive than over rev in the air.

So, I guess I just answered my own question and will do the extra work to fit my motor in the transom well.

Thanks again people, interesting to see how others look at the same thing with different perspectives.

On Vacation
08-11-2003, 08:00 AM
If the well area is just covered anyway, if you don't cut it out, then use a well in it. Does it show the motor rigid in place and steer with a tiller. Kep in mind the amount of room that is required for motor sterring in the well, though. Engines will need some area for venting in well. Has the other boats , built from this design, carried a motor on a bracket? Motors take a beating from the elements on the brackets in salt water.

Carl Simmons
08-11-2003, 02:45 PM
I have a lightning and needed to mount a trolling motor for moving in/out of a small sheltered bay. I made a mounting bracket that slips into the rudder gudgeons. I bought a couple of Transom Pintles to attach to the mounting bracket. When I get out in the wind I'll pop off the trolling motor and drop in the rudder.

Carl.

Danny Quin
08-12-2003, 05:48 AM
Jeff,
Does the outboard push the Golant Gaffer against a tide?. I'm building mine up in Central Qld and seeing you have one instead of an inboard is making me think it might be the way yo go.
while I have you, what timbers did you use in the keel?. Danny

Banjo
08-12-2003, 07:52 AM
Originally posted by Oyster:
If the well area is just covered anyway, if you don't cut it out, then use a well in it. Does it show the motor rigid in place and steer with a tiller. Kep in mind the amount of room that is required for motor sterring in the well, though. Engines will need some area for venting in well. Has the other boats , built from this design, carried a motor on a bracket? Motors take a beating from the elements on the brackets in salt water.G'day Oyster, the plans have the transom cut out for the motor head to the port side, far enough from the rudder so it wont get turned into match sticks but as close to center line as feasable.
There is a well built in front in the cockpit seat that is self draining and big enough for tilting up when not needed, and for some side movement for steering.

It's a fairly open type of well that should allow good air flow.

Any other boats built?
Nope, as far as I know mine will the first in Aus. There are two more being built in NZ and one possible starter in USA later this year.

I'll have to get some pics happening, I have been all fired up with the building that I forgot all about taking progress shots!