Hi all
Your guidance would be appreciated. The 4 diesel mechanics / electricians i called today all have a wait list of 4 to 6 weeks so my thinking of re-powering my 20 ft couta boat with an outboard has gone up a notch. I don't really motor a lot, only in and out of the marina. she has a displacement of around 2000kg and currently has an old 15hp volvo, a stern hung rudder and a draft of 2ft, board up and a beam of 7.5ft. I would prefer a lighter motor as i will likely be taking it off gather bracket after each sail.
So if i pull the pin, my query is what kind of hp should i be looking at ?
Cheers. KK

What's wrong with the present engine?

Gary

The Tohatsu Sail Pro 6hp 4 stroke has to be a contender if you want to take it off the transom bracket each sail. See here comments and details. This should get you in and out of the marina ok in less than 15kts and not much swell but at 2t displacement will be battling to get you back home in a mongrel 30+kt westerly and associated seas.

forums.sailboatowners.com/threads/tohatsu-sailpro-review-log.186225/

www.centraloutboardservices.com.au/6-hp-tohatsu-4-stroke-sail-pro/

If you don't want to take it off the transom bracket the Yamaha high thrust 9.9 4 stroke would be hard to beat - they are available with optional power tilt as well as the standard elec start...............need a solid transom bracket............had one of these on a Columbia 22 and it was a beast.

www.yamaha-motor.com.au/products/marine/outboard/high-thrust-four-stroke/t9.9

Just now camping on Dawson river using Tohatsu 6hp,4st. Pretty good motor.
Having 6 years 2tons yacht Aquarius with 9.9 Yamaha , I was extremely happy with it, but wouldn't recommend. It's heavy and was not needed it, boat was overpowered.

I would have a look at the Volvo first. Sounds like it could be a MD7 a or b. Nice heavy motor in the right place in the boat.

couple of questions:
existing prop size & pitch
gearbox ratio
max existing engine speed ( MD7 prob 2000 rpm)
can you get to hull speed with existing setup
desired cruise speed

putting an outboard on a Couta boat will get you strung up and quartered by the purists for sure, especially on an outboard bracket.

The Yamaha electric tilt has a tall or deep mount bracket to enable the ram to get leverage, and the 9.9 high thrust is too heavy to considering taking on off very often.

Your boat is the definitive 'put put', you need to stay inboard IMHO.

Your boat is the definitive 'put put', you need to stay inboard IMHO.

That is the post that I was hesitant to write.
thank you Crusty.

KK if the Volvo is completely rooted, electric might be the way to go, internal mount, pod or outboard. What's the Volvos problem ?

Hi. Many thanks for your thoughts. My main issue is reliability to get in and out of my marina berth - not really feasible to sail in. My 1st thoughts were oars, but the recommended length of 12.5 ft are hard to find and a little expensive. Not interested in making my own and at 2000kg she may be a little hard to push along, but with a background in rowing, I'd be happy to have a crack. 2nd thoughts were for the outboard. I've read lots of pros and cons of outboard/inboard argument, and wasn't looking to re-hash it here, but I was not looking to get rid of the volvo, only to get a plan b, when things go pear shaped, particularly with a comprehensive lack of mechanical ability and a now 6 week wait to get a mechanic down to look at the inboard (thank you COVID...).
So, RL i was thinking somewhere around 6 to 8hp, and that tohatsu you tipped sure looks the goods, and light too at 25/26 kg. I will investigate further. Thank you!
cheers. KK

But what is wrong with the Volvo? Any Volvo will be more reliable than any outboard long term. Download the manual and look at a few Youtube videos on your particular motor. If you have to, lift out the motor and take it home, pull it down and learn as you go. As an emergency propulsion consider a sculling oar.

Kevin's 31 footer weighs 8 tons.
He has no engine so he sculls.

That is another option Keelkicker.
Will win you lots of brownie points too.

Select to expand quote

Ramona said..
But what is wrong with the Volvo? Any Volvo will be more reliable than any outboard long term. Download the manual and look at a few Youtube videos on your particular motor. If you have to, lift out the motor and take it home, pull it down and learn as you go. As an emergency propulsion consider a sculling oar.

+1. The worst that will happen is that you will take a stuffed engine out of your boat and your clothes will smell of diesel. The best is that you will learn some valuable diesel mechanic skills, or maybe get more confident in taking a spanner to the metal lump.

Regarding the sculling oar - it is feasible for slow manoeuvres in good conditions for larger, heavier boats, see here

+1 for the sculling, 2 x 12" sweeps would be all but impossible in a marina situation. I find it a good option when rowing out to a vessel to ship which ever oar is ship side and use the other oar to scull the dingy sideways. And a note on sculling dingys is to have the notch or rowlock on the transom of to one side so you can keep your weight centred, and if you have a tiller it's an obvious position, Portside is favoured so the left hand can operate the scull and the right is free to handle lines. Not as powerful as rowing but it's a skill that has its place

come on KK, I think everyone wants to fix your diesel.
I know nothing more than they can rip your arms off when you try to manually start them and they can run away and explode into millions of pieces, so i'm no help at all.

If you were considering getting a diesel mech out, must be worth spending money on?
Have a crack, i'm sure there are plenty willing to give you some pointers??