new dinghy - info please

[Even Chance]

I just got myself a second-hand Seabo by Silvermarine inflatable dinghy with a wood floor and an inflatable keel that looks like a wee rib style.
Its a model type - MS-81275A
Never heard of one before now, but it was dirt cheap.
Its a wee bit scruffy and needs a good clean but its all there and in reasonable nick.

I have a long shaft Yamaha 2s 4HP engine that I use on my E-Boat. Can I use it on the dinghy as well? If so, will it plane?

This is all new to me. Never had a rubber boat before. Thanks in advance for the info....

 

[Tranona]

Simple answer is No! Inflatables are made for short shaft motors. Transom height to waterline of 15". Long shaft is 21". It may work, but increased immersion can lead to exhaust backpressure - poor starting and running. Probably more important is the prop is too deep and limits you in shallow water.

 

[sarabande]

it's bit marginal with that kind of HP, as it depends on the waves and the weight on board.

With a long shaft o/b you might find that the cavitation plate is well below the bottom of the transom, and tends to lift the bow up a bit. Shouldn't be too much of a problem though to trim it out with crew for'd, or adjust the rake of the shaft.

Have fun !

 

[Even Chance]

Bit more info:-

Water depth aint a problem at all.
The fact that its already on the E-Boat is another, and the fact that the E-Boat aint the biggest yacht to be lugging a second outboard around on is critical!!

 

[Tranona]

You can but try.... but you have to ask yourself why the designers bother to design it for a particular type of engine in mind! A 22ft sailboat and a little inflatable dinghy are two entirely different kinds of boats so not surprising their engine requirements are different.

 

[Even Chance]

If it doesnt work, I do have a wee short shaft seagull that I can throw in the aft locker!!!

 

[Tranona]

Seagull much more sensible for a dinghy - however, will not plane. You usually need 6hp to plane with any load. Seagulls are actually made in 3 lengths. The shortest is 13" but the most popular (40+) are 15" with the ability to shorten using a collar - useful on some inflatables where the transom or mounting boardis even lower than standard.