Inboard/outboard swap

[Guest]

Hello and thanks for reading - I have a Leisure 23 grp bilge keel sailing cruiser which weighs 1.8 tonnes. Its engine is a 6hp Lister diesel single cylinder inboard which smells, is noisy, and its vibrations are splitting the bearers. We use the boat on the river Tamar where currents are not bad, but moorings are a bit of a treck up from the sea. I am seriously thinking of swapping it for an outboard and would appreciate thoughts advice on what size to use. One boat yard says 15hp 2 stroke long shaft, a second boat yard says a 9.8hp Tohatsu long shaft will be fine. What do you think ?
Happy Christmas

 

[Guest]

My Snapdragon 23 was fine on a Mercury 7.5 Sailpower O/bd. Another friend had a Mercury 9.0 Sailpower O/bd
Basically you will need a long shaft and its best to go for the Sailpower type that has greater thrust instead of revs ..... revs are for the speedboat guys !
Anywhere around the 7.5 and up should do the trick.

I even cut a well into the aft end of the cockpit to take mine after nearly falling in the drink a few times lifting on and off the transom lifting bracket ! Worked excellently and gave incredible manoeuvreability .... prop ahead of the rudder etc.

 

[LadyInBed]

Re: Inboard/outboard swap - dont do it!

Changing to an O/B is ok on the face of it, but I would re-engine with a Yanmar 1GM10. The cost may appear more but by the time you have re-engineered the boat for the O/B, taken change in resale value, loss of reliability, better battery recharge ability, cost of fuel and range (depending how much petrol you want to be loaded with) into account, I bet the scales even up.

 

[Jcorstorphine]

I had a friend who had a Leisure 22 fitted with an 8HP Mariner which was ok in most conditions but the prop did tend to come out of the water when there was any sea running. Not sure as to the length of the shaft. One point was that he had to use the pivot on the engine for getting in and out of the marina as the steering was a bit iffy at low speeds. Left a lot of room under the cockpit for storage.

The point made by one of my fellow PBOs is very true in that you may reduce the resale value by having an outboard instead of an inboard diesel.

JC

 

[Guest]

In my post about the Mercury Sailpower etc. I forgot to mention that I did have an inboard previously. A Vire 6 ..... yep I had one of those petrol jobs !!!!

When I removed it I left the bearers and shaft exit a nd blanked it off, so that later owner could return to inboard engine easily.

The o/brd was mounted with enough cut-out at the hull exit to allow steering of the motor ..... you cannot imagine how much this improves manoeuvring ! I used to slot my 23ft into 25ft spots on pontoons ! I could 'back' all the way out of marinas, even my 9 year old son backed all the way out of Ryde Marina from the inner HM end !

As to resale value .... if the bearers are splitting and you have problems with present i/bd .... that will reduce your resale anyway ... and actually a lot of people are going back to o/bds on the smaller boats as its easier to service, easier to repair, replace etc.

I still overall prefer a i/bd engine, but after having 3 boats with o/bds, cannot condemn them and see their great advantage.

Look around and talk to people ....

 

[Guest]

Peter, I understand your thinking and good luck with whatever you decide to do. I do share the other Posters' points of view in that a boat with a diesel inboard is considerably more attractive to prospective purchasers than one with an outboard. It sorts the men out from the boys, so to speak.

I have used an outboard on previous boats (when the inboard was out on overhaul) and battery charging, low centre of gravity, ease of fueling, economy of running make the inboard a better bet.

Also, no matter how good the outboard, you will never have the same amount of torque delivered from an OB as from a diesel. Prop size is limited on an OB and I have seen the situation where it was impossible to reverse off a mooring trot with a strong stern wind, because the outboard prop was never going to be as efficient from a standstill as the inboard. When faced with a head sea the inboard will win again.

By the time you have made your fourth trip to the petrol station with the tank when the rest of the crew have been in the pub for an hour, you might regret your decision to go with the outboard.

Best regards

KCA

 

[Boathook]

Re: Inboard/outboard swap - dont do it!

Outboards are reliable. Like most things it is the owners!. I have never had one letting me down and I have watched the waves covering them.
Go for a 4 stroke with a high thrust prop (its large diameter and geared down) and is designed for sailing/displacement boats and also normally gives full thrust when astern. Fuel economy could well be 1 gallon every 3 hours or better.

 

[rbrooks]

I' use a 3.5hp yamaha o/b on my Mistral 22 and never felt underpowered, but I only use it to get in and out the marina.
Some of the posts are suggesting 7hp and up, what kind of weight are these motors? just thinking of what it would be like to lift one off the engine bracket.

R

 

[Guest]

Outboard advantages:
Lighter, cheaper, easier to work on (lift it of and take it home), less holes in the hull, cleaner/more quite inside, cleaner fuel,
I think 6 hp will do the job (less hp is less weight, cost and place) and please do stay away from 2 strokes!
I speak with personal experience in all cases...


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