Motor on mirror

Hi,

I am not sure if this belongs here. But I found no better place. Having a 5PS Honda BF 4.5 long shaft outboard weighting 27kg would that work on a mirror?

Thanks for sharing your thoughts or expierence.

Timo

Hello Timo, that sounds a bit heavy to me! Also, it's not just the weight that's at issue. The transom isn't designed to take the thrust of a motor of that size. I guess if you are running it on low revs it will be OK. I did run a Mariner 4 on the back of my Mirror, but found it quite scary!
Best wishes,
John
Red Kite 53814

CaptainZ's picture

Hi Timo,
this is too much weight on Mirror's transom. The dinghy was not designed to carry so much weight. Your outboard is I am sure a 4 stroke.. If you can find 2-3 HP two stroke that would be plenty of power.
Maybe 4 stroke Honda 2HP , that would be the most I would put on. I have an old Tomos 4.5 2 stroke which is about 15kg. Sometimes I am using my vintage Seagull Forty plus which is a bit less heavy at 13 kgs. Right now I am thinking of getting an electric trolling motor with medium size battery - this way I can have the battery at the best spot ( close to the center of the boat) and the (fishing) trolling motor would be enough when the wind dies..... my 25 cents worth :)

PuffinInTegel's picture

Hi Timo,
wouldn't adding an engine to a Mirror cause a lot of beaurocratic hassle in your area anyway?
Würde die Verwendung eines ABs an einer kleinen Jolle am Bodensee nicht sowieso zu umfangreichem Papierkram führen?

beermatt's picture

I broke one of my transoms with a ~5hp Seagul Forty Plus (if i've remembered the model correctly).

The shaft length makes a difference because of the leverage. The closer the prop is to the hull the more it is pushing the boat directly forward, the deeper the prop is in the water the more it tries to tilt the boat backwards, putting more stress on the transom.

If you're desperate I would estimate a well built transom in good condition* could cope with it running at low speed ONLY. (*The strength varies greatly from Mirror to Mirror! Depends how heavily built it is and what condition the wood & joints are in.) A lightly built or bad condition transom could fail under the weight alone, even a well built good condition one would probably fail at maximum power for any length of time.

Also worth considering is it's not just about the boat, check the user manual for the outboard for what it says about water depth, there is usually only a few inches of tolerance the impeller and exhaust is designed to contend with. Running a long shaft on a short transom (too deep in the water) can damage the motor.

These days I run my short shaft Suzuki DF2.5 (four stroke) on my GRP mirror, and even full speed it's never given any problems. 2.5hp is more than enough power for the hull.