Question about O/B Motors

[mnwild]

I have a question reguarding O/B motors, what is the main differance between a long and short shaft motor, Obviously one is longer than the other but is there a differance in performance?? Right now I have a Evinrude SS 6hp on a 14' and looking for something bigger.
Any info is appreciated.

[bigmouth]

I will take a stab at this. I believe the only reason they make the two is for the depth of your boat. Deeper boats need to have a longer shaft. It would also depend on what you are doing with the boat. A 14 flat bottom used for duck hunting you would for surely want a short shaft. Other than that I don’t think that there is a performance difference.

[mnwild]

thanks for the reply, I didn't think there was that much of a differance. Maybe more people will put their 2 cents in.

[jknoll]

Shaft length is determined by the height of the transom. If the transom goes straight across, you probably need a long shaft. If there is a dip in your transom, you probably need a short shaft.

[Wavey Davey]

Short shafts are for 15" transom heights,
long shafts are for 20" transom heights.
The best performance is acheived when the cavitation plate on the motor (the fins above the prop) is at the same height as the bottom of the boat.

There you go, not bad, eh?
(my brother used to be a marine mechanic)