help with shaft length for a kicker

[silveraire]

looking for a kicker for my boat. Would like to mount it beside my outboard on my transom. I have a 20" transom. I have found an 8hp jonson sailboat kicker with a 25" shaft. Right price and in exellent condition, but am concerned that the shaft will be to long. Thank you for any help given.

chad

 

[Sea Rider]

Re: help with shaft length for a kicker

Not a big tech issue being engine 25" and transom 20", you are not going to plane with that small engine, just to push in a possible emergency, go for it. We use 3.5-5 HP (20") long shafts on (15") short shaft transoms as aux and kicks perfect.

Happy Boating

 

[JimS123]

Re: help with shaft length for a kicker

I've had kickers mounted on brackets, and right on the transom (like you are doing) as well. I've also tried different heights. Some work better than others, and some work poorly.

Your transom may be 20" in the middle, but its probably closer to 15" where you will mount the kicker. A 25 will be too deep in the water and it'll probably lug. I wouldn't do it.

Whatever motor you chose, you WILL need a sailboat prop though.

 

[Sea Rider]

Re: help with shaft length for a kicker

If you have already measured you transom tip to bottom to be 20", then if you place aux sdieways to central engine your available transom height will be probably 1"-1.5" " higher and work perfecty. If possible for your peace of mind and not let down that magnificent purchase opportunity, place that 08 kicker at back transom and test for yourself. Will see that motor doesn't have lugging issues whatsoever with that height difference.

Happy Boating

 

[ezmobee]

Re: help with shaft length for a kicker

Yeah, in my opinion, that motor sounds IDEAL. You want to be able to mount your kicker a little higher so it doesn't get swamped by waves yet still have plenty of shaft in the water.

 

[ondarvr]

Re: help with shaft length for a kicker

The length of the kicker is only an issue in a few cases, and really only if it's too short. Too long and it will just work better, deeper in the water means more clean water to the prop and it won't be coming out of the water when it's rough. The drag from more of it being in the water will make no difference, it won't go fast enough for it to be an issue no matter how you use it.

 

[JimS123]

Re: help with shaft length for a kicker

If you have already measured you transom tip to bottom to be 20", then if you place aux sdieways to central engine your available transom height will be probably 1"-1.5" " higher and work perfecty. If possible for your peace of mind and not let down that magnificent purchase opportunity, place that 08 kicker at back transom and test for yourself. Will see that motor doesn't have lugging issues whatsoever with that height difference.

Happy Boating

The logic here escapes me! Its a V hull. Its 20" in the center at the main engine. Its LOWER at the kicker location, not HIGHER.

Go measure it.

Then google using a long shaft on a short shaft transom. Granted it'll not plane the boat.

OK, go try it and report back.

 

[ezmobee]

Re: help with shaft length for a kicker

Granted it'll not plane the boat.

Bingo

 

[Sea Rider]

Re: help with shaft length for a kicker

The example is measured at an imaginary horizontal line from bottom keel to kicker location to form a 90? angle. What counts is the transom height measured from boat's lower keel to upper transom not hull's less lenght to where kicker will be positioned, nobody is pretending to plane with such a smalll engine. Just to push in an emergency at the most 7 knots.

No need to google, this issue has been tested and talked about to near ad nauseam in the inflatables-rib forums, to make it short, the only issues using a long shaft engine on a short shaft transom will be: (1) increase water drag against leg if water is passing above small plate (2) have excesive leg water splash sideways or water entering transom through engine's sides, (3) prop nicks, prop shaft bends, leg damage while hitting objects boating on shallow waters.

Happy Boating