Tohatsu MFS9.8A3 UL 9.8HP 4STR UL (£2,141.41p) in westerly centaur with dead engine

bless you

contessaman said:
I said I wasn't going to play anymore but I can't sit this one out.

Melges vs centaur. interesting comparison.

As I said in an earlier post in a lightweight sportsboat (like a j/80 or a melges) I would have an outboard. The J/80 I have sailed on has a 3.3 tohatsu. I dont see the need for a well at all? transom is fine. The outboard gets the boat off the pontoon and through the lock. the sails go up. the outboard comes off and goes in a locker. its no longer needed. with the weight and the strength of the large crew that boat doesnt need an engine. in some ways, to a lesser degree seajets anderson is much the same. It will perform well enough under sail alone that the outboard is fine.

Im not slating centaurs, they sail well for what they are. But find yourself on a lee shore in a nasty short chop or caught wind against tide and you are going to need the motor to get you out of the poo (particularly if short handed) and why the hell not - if youre not racing I really dont see the catch.
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bless you for caring 16 pages in on nthis surprisingly long thread

you are one lovely compassionate bloke

but, since you ask,

first of all I would do my utmost to avoid those circumstances using 50 years of boat experience

should I find myslf in the condition you describe then I would unfurl a small bit of genoa

make that uber reliable Tohatsu dig in for all it was worth

and , in a series of tacks,crab my way way off the lee shore

should that fail then I would run the sucker aground and abandon ship clutching nothing more than the memory cards from the cameras

just as I would do in the slug or the Minstrel

I do hope that touches every base

now then

PBO is aboard with this project

I have sent an email to Tohatsu asking if they are interested

I shall relay their reply to you chaps

and tommorrow I shall send another to West systems

all we are lacking then is a decent Centaur with a jiggered engine - does anyone onow of one apart from Tam Lin

a warm shed, a weekend and the good will of this forum

Dylan
 
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"PBO is aboard with this project"

Funny that! Nostro was ostracised when the "forum" thought he might be making money out of a book researched on the forum?.?
 
Hadenough said:
"PBO is aboard with this project"

Funny that! Nostro was ostracised when the "forum" thought he might be making money out of a book researched on the forum?.?
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not sure what your point is

but so far the forum has expressed some concern for my sanity

a few blokes have had a jolly good think about it and seem to believe that it might work - badly

even more blokes have given the reaction - "don't be stoopid" and "it will never work"

what it has shown, through the longevity of the thread is that it is an interesting concept

I am very happy to hand the project over to some-one such as yourself who has trhe drive, enthusiam, organisational skills and good will to follow through

I assume PBO would be just as happy for you to earn the £200 for the two pages as for me to do it

very happy to pass on the contact details of the blokes at Tohatsu (early stages on that part)

It would be great if some-one did this before I get the jig saw out


D
 
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"It would be great if some-one did this"

It wouldn't! If you spent as much effort on understanding simple diesel engines and learning a few basic mechanical skills as you did theorising about this project there would be no project!
 
Pretty certain you will lose a fair bit of torsional rigidity in the hull. A quartering sea will impose all sorts off stresses on the part of the boat you have cut out. You will need so much bracing to to counter the twisting forces you will add a lot of weight where you have decreased the buoyancy.
If you don't brace the well adequately, you may find a quartering sea twists the hull and fractures the well joints.

Also, you will use so much more petrol trying to push a heavy boat compared to Katie L. How will you buy enough with the purchase restrictions on garage forecourts?
I hated having petrol on my old boat.
 
dylanwinter said:
that is what I thought

I do hope tomorrow finds you in a happier frame of mind





here is a link that came my way

http://atomvoyages.com/articles/improvement-projects/249-outboard-1.html
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Ŷ
You are right I am a bit crabby tonight! Apologies. However, I do think that you need to exorcize your obsession about diesel inboard engines and ropes around the prop. Have you considered a triple keeler? Seadog 30 springs to mind, unlikely to get a rope around that prop, 1m draught and sits upright on anything.
 
Whilst it's an amusing and utterly potty folly to contemplate, it hardly strikes me as PBO material.

You spend more than necessary to compromise a boat in many different ways, more than likely reduce its performance and change the fuel source from one which is benign to one which is volatile. There's nothing vaguely practical about it as far as I can see.
 
Simondjuk said:
Whilst it's an amusing and utterly potty folly to contemplate, it hardly strikes me as PBO material.

You spend more than necessary to compromise a boat in many different ways, more than likely reduce its performance and change the fuel source from one which is benign to one which is volatile. There's nothing vaguely practical about it as far as I can see.
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I beg to differ. There are lots of older boats with ageing inboard diesels which would cost far more than the boat is worth to replace. It's not uncommon to see outboard brackets on the back of them, but that brings all sorts of problems, well listed here, many of which (accessibility, flow over rudder, propeller staying in the water) could be sorted by a well. I doubt if many people in that position would be buying a brand new Tohatsu, but it seems very PBO-worthy to me to investigate the possibility of retrofitting an outboard well.

If Dylan is keen enough to do it ... good luck to him.
 
Habebty said:
Pretty certain you will lose a fair bit of torsional rigidity in the hull. A quartering sea will impose all sorts off stresses on the part of the boat you have cut out. You will need so much bracing to to counter the twisting forces you will add a lot of weight where you have decreased the buoyancy.
If you don't brace the well adequately, you may find a quartering sea twists the hull and fractures the well joints.
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I wouldn't be too worried about that, myself. As long as he makes sure the corners of the well are rounded with a reasonable radius (c.f. Comet airliner) and sticks a bracing ring round the inside when he cuts the hole, I don't think it will be a problem.
 
JumbleDuck said:
I beg to differ. There are lots of older boats with ageing inboard diesels which would cost far more than the boat is worth to replace. It's not uncommon to see outboard brackets on the back of them, but that brings all sorts of problems, well listed here, many of which (accessibility, flow over rudder, propeller staying in the water) could be sorted by a well. I doubt if many people in that position would be buying a brand new Tohatsu, but it seems very PBO-worthy to me to investigate the possibility of retrofitting an outboard well.

If Dylan is keen enough to do it ... good luck to him.
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Good luck to him indeed, but the practical solution for such boats is to rebuild or repower, either of which could be done for around £1500. Even starting with a cheap old outboard of questionable reliability, you could well spend close on the same money by the time you've done the major mods and paid for all the incidentals, and still end up with the issues I mentioned.
 
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Just caught up with this thread and read all the posts which qualifies me to answer the poll in another thread.
Sorry Dylan, not ready to sell my Centaur yet and am confident that the engine will be repaired over the winter but will be watching your progress with interest in case it goes wrong again!
If it does then I have the A22 as backup!
 
Habebty said:
Pretty certain you will lose a fair bit of torsional rigidity in the hull.
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Bearing in mind that the forward bottom of the well will have to be shaped to match the shaft tunnel's shape, I think there's probably redundant rigidity down there which Dylan can benefit from, especially if the sides of the well land on the edges of the cockpit trench, and the back of the well lands on the wall of the aft locker.

It's still going to make the cockpit tiny and noisy though.
 
JumbleDuck said:
I wouldn't be too worried about that, myself. As long as he makes sure the corners of the well are rounded with a reasonable radius (c.f. Comet airliner) and sticks a bracing ring round the inside when he cuts the hole, I don't think it will be a problem.
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He's going to be doing better than a bracing ring - he'll have the structure of the well itself, some kind of tube running from the bottom of the hull to the cockpit sole. That's loads of additional reinforcement. Should the hull need it, which I doubt.

(To be clear, I'm only thinking of cutting a hole just big enough for the business end of the engine to descend into vertically - not disembowelling the whole after end of the boat.)

Pete
 
the cockpit

Twister_Ken said:
Bearing in mind that the forward bottom of the well will have to be shaped to match the shaft tunnel's shape, I think there's probably redundant rigidity down there which Dylan can benefit from, especially if the sides of the well land on the edges of the cockpit trench, and the back of the well lands on the wall of the aft locker.

It's still going to make the cockpit tiny and noisy though.
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you are correct

I think you could take the the strength of the cockpit and transfer that down to the hull

the cockpit on the slug was a fantastically strong element

so structurally that is where some extra stiffness will come from

- and a fairly easy large area bond on a flat surface to the edge of the cockpit walls

the well might be a bit large - so it might need some inner less structural elements to reduce the amount of water slopping around it

I want to have a gppd crawl around inside the back of a Centaur now to see how much lines up.

I am a long way from landing this as a winter project and really do not think I will get a chance to try it

but....

I am a patient man

D
 
I apologise in advance for posting without reading all 18 pages it might have been said before.

My firts impresion are you nuts? sorry rather rude.

Cutting a hole to put an outboard through in a perfectly sound hull which was not designed to have a hole for an outboard is going to be very difficult, the structural complications are huge.
It could be done, get a skill saw or chain saw and have at her, trouble is you now have to replace all the strenth you have just removed.
Making the hole round rather than square, will be stronger and less likly to stress crack.
Suround hole with doubling plate, and or lotts of extra glass and resine. difficult and expensive to get plate fair to rounded hull.

Ok you make is strong enough. now you have to make it watertight up to cockpit sole again difficult. probabaly expensive.

Forget the well.

Genuine question why do you want a well?

I understand the outboard. for a small boat i would choose an outboard.

if I were in the position of needing a new motor for a 30ft sail boat.
the expense of a diesel. compared to an outboard.

I would by a Yamaha saildrive 9.9(if avalable in UK)
Most fishing charter boats on west coast use them comercialy. They want to go slow in strong currents holding position the saildrives work very well for this purpose.
They are desigened to push a big boat slowly ie have large course prop and produce lots of power at low rpm.

I had one on my 24ft C&C pushed along at near hull speed with less than half throtle.

Forget the well.

Hang the outboard on a bracket.

The right bracket will hold it high enough out of water and have prop in.

Manouvering a sail boat with an outboard on a bracket is easy.

The trick. it tight spaces, Go backwards, steer with the outboard, you can see wher you are going.
All the other boaters will think you are a bit daft.

PS don't let go of the tiller.
 
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Simondjuk said:
Good luck to him indeed, but the practical solution for such boats is to rebuild or repower, either of which could be done for around £1500. Even starting with a cheap old outboard of questionable reliability, you could well spend close on the same money by the time you've done the major mods and paid for all the incidentals, and still end up with the issues I mentioned.
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Well you could, I suppose. But I think there will be plenty of people around with old boats up to 26' who would be interested to know if an outboard in a well would work for them. Many of these boats would have had an original choice of inboard or outboard, so "more convenient outboard" wil be worth investigating.

I'm not sure that I would consider the sort of inboard engine you could get and fit for £1,500 to be much of a solution.
 
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