Long shaft or short shaft?

[ck85abc3]

Short shafts are 20 inches long and long shafts are 25 inches long.

What are the reasons for wanting a short shaft or a long shaft?

 

[jbjennings]

Re: Long shaft or short shaft?

Needing a short shaft or a long shaft has to do with the height of the transom on the boat you're mounting the motor on. Short shaft motors fit 15 inch transoms, long shaft motors fit 20 inch transoms. If your transom is 20 inches and you have a short shaft on it, your motor won't stick down far enough below the bottom of the boat for the prop to get a good bite or the water intake to get enough water to cool the motor. Too long a shaft on a 15 inch transom puts more motor in the water and increases drag, slowing down your boat.
At least that is my understanding.
JBJ

 

[ck85abc3]

Re: Long shaft or short shaft?

Thanks, that makes sense.

I wasn't sure if it had something to do with small river or shallow water fisherman wanting the short shafts.

 

[tashasdaddy]

Re: Long shaft or short shaft?

you now have short is 15, long is 20, then they now have 25 and 30 inch shafts.

 

[JB]

Re: Long shaft or short shaft?

A 15" shaft is SHORT, 20" is a LONG, 25" is EXTRA LONG and 30" is XX-LONG.

Each is for a transom that is VERTICALLY that tall from keel to transom top. Transoms that are not vertical (few are) should not be measured on the surface, but in a straight drop from transom top.

 

[Navy Jr.]

Re: Long shaft or short shaft?

you now have short is 15, long is 20, then they now have 25 and 30 inch shafts.

Yes, the 20 is considered Long, and that may have been fine years ago, but the boat we wanted (and bought) had a 25" transom, so XL or Extra Long for us.

That extra transom height makes a big difference on a big lake on a windy day with big yachts cruising by. The bilge was bone dry.

 

[Solittle]

Re: Long shaft or short shaft?

Thoug not the best set-up you can run a longer shaft engine on a shorter shaft transom but not the reverse. I run a long shaft 9.9 on a short shaft transom.