Powering a 25 with a tiny outboard?

[notsowindyyet]

Has Ever someone tried to Power a 25 with a 5 to 8 HP outboard attached to the bathing Plattform?

It should be enough to propel the vessel to 70% of Hull speed and the distance to the ear and the aft cabin Block should make it a quite silent Alternative for use on chanals and calm seas

.. Way more econimical Than elektric drive.

[kerrye]

We use a 9.8 on ours. Works fine. I think an 8 would also work

[notsowindyyet]

cool! now am I very curious about the details!

- special mount to the hull to .. i dont know the correct english term... to "cover" the forces - or did you simply hang it onto the bath platform?

- is it a tiller, and you use the main rudder, oder is it complete with remote steering and throttle? (if so how did you bring the cables to the pilot house?)

- where did you put the gas tank?

- how fast do you go and how much does it consume?

- is it really a lot less noisy, as I assume?

- what about boat trim and weight?

- long shaft?

- mounted at one side or in the middle?

thanks a lot for you elaboration!
If it is as quite as I hope it is, that would make traveling so much more enjoyable...

[stmbtwle]

It should work fine depending on how "tiny" the outboard is. I once pushed a 35', 9 ton houseboat with a 4, just to see if I could do it. I got 2 knots in calm water (per GPS). Another test with an electric trolling motor (30# thrust) got me 1 knot. The problem is more of control, steering and stopping. You'd definitely want a motor with reverse.

Bear in mind that an Albin 25 is basically a sailboat. Look around the marina and see what size auxiliary your rag-boat neighbors are using.

I would think a 15 or 20 would be a viable repower option for an old A25, instead of an expensive diesel. I'll bet a cookie someone has already done it.

For that matter I think a 24 or 25 footer built for a small outboard might be a good setup. You'd save weight and cost, and gain space and trailerability.

Not an Albin, but... https://www.tohatsu.com/news/seiko.html

[notsowindyyet]

Hi...
Not to be misunderstood...
The albin was repowered 9 years ago and i bought her mainly for this reason. She will be Our "longttravel adventure" boat. And She.. And we... Can take "some".

But i am thinking for the calm and relaxed Wellness moments to use the outboard to make the ride less noisy.
5-6knots Would be great.
I Heard about 3 poeple who have done it know. Between 5 and 8hp.
I was only woundering how those guys manage to control the ob.
Simplest Would be climb... Start...use Main rudder... Climb... Shut off...
But there Are more comfortable Set ups

And i Would prefer a 20 and use it only at 2000 Rpm But weight is an issue so far back at the Hull.

I am thinking about 40m anchor chain as a counter wait in the bow ... But... That does Not make the boat much lighter...



About your link:

Perfect thinking! We allready have a grand r460 as the tender to albin

[stmbtwle]

I don't think the rudder would be that effective unless you removed the prop, not really an option. So I'd find a way to connect the outboard to the existing steering, so when you turned the rudder the outboard turned as well. I think I'd talk to someone who installs and rigs outboards.

Considering the turbulence behind the dead prop, an off-center outboard might better.

[notsowindyyet]

Ouch.... I forgot completely about the deadprop...Will cause quite some drag at 6 knots

[DCatSea]

Somewhere on AOG is a posting showing how the European owner of a 25 rigged a small outboard as secondary power, on a drop down bracket or direct to the swim platform on a block of wood. He then clambered over the taffrail and peered along the starboard side to steer with the attached tiller. I assume that you could install a tiller extension and sit on the aft cabin roof to the same effect (maybe using a coat hangar to go from forward to reverse Would not want to do any fancy steering tho'.

[WillieC]

How about a bicycle arrangement that attaches to the shaft via chain and sprockets? Pedal quietly in the luxury of the cabin...maybe even attach the rudder to the handlebars. We could be onto something here! I know I could use the exercise.

I have thought of putting some kind of brake on the shaft so I can change direction without the attendant clunk when the prop is free-wheeling in neutral while in motion. But that's a whole nother project.

[notsowindyyet]

Bad news.

I have found a Research and Tests about foldable props compared to Standard props.

The Standard in the test produced 200N breaking force at 6 knots. If rotating in neutral it was still 100.
That Was 40% (!!) of the force the complete 34feet boat produced!

Foldabes were at about 5% of That.

Some dirty calc gives me 400 and 200N For the albin.
That is a lot to overcome.

I can only assume this to be 60-70% of the resistance of the albin?!

I called one of the Best folding prop companies in germany.
They said they cant advise me to Do That because these pops Are Not Designed to last long on Motor Boats......

Cost... 3000euro...

He said Best Would be to put That money in noise canceling Projects.

The ob at the Stern is a homebringer... Not more.

[stmbtwle]

I have to agree on the "noise cancelling projects". It is probably the least expensive and the most satisfying in the long run. You'll get the benefit all the time.

Allowing the prop to windmill can also damage some transmissions, can't speak for yours.

[WillieC]

"The ob at the Stern is a homebringer... Not more."

I think that pretty much sums it up. I have read somewhere about some who have considered or have completed the transition to a full outboard, eliminating the inboard altogether. Waiting for reports on nuclear powered conversions.

[kerrye]

Ours is on a drop down gas shock assisted mount to the port of the swim platform which goes about 2/3 of the width of the stern. I put the fuel tank on top of the aft cabin. It's an electric start tiller control so I stand on the swim platform to control it. I haven't experimented with the effectiveness of the main rudder under way. We use ours for manoevering in tight quarters and for a back up engine in case of a main engine problem. We have used it twice under those circumstances and it performed perfectly well. I don't know what speed it held at what amount of throttle. Perfectly adequate to my mind but no exact figures. If I were more ambitious I would rig a stick control at the main helm so i could control the throttle and turn the engine by moving a stick back and forth. That would be fairly simple but I haven't found the need to do it yet. I really like the option of a turnable prop in tight quarters. This may just be an indication of my inadequate skills but the ability to turn much more tightly at slower speeds seems to be a significant advantage.

[kerrye]

Red neck version: https://www.youtube.com/watch?v=WGPHabipJlY

Elite version: https://www.wholesalemarine.com/ezy-gli ... gLw6_D_BwE

[notsowindyyet]

ok - My concern was not manouverability.
I wanted to make it the "low noise dutch canal power plant" and reserve the main engine as "high power off shore engine" ... something like that.

I came up with the idea because some river boats are build like this - with an ob "far away". but you "can't" buy those boats if you have only the slightest interest in real boating.

so...maybe I forget about the OB as a long distance engine and make the main engine as silent as possible.