School me on short shaft vs long shaft outboards...

[Josh]

So, I don't really get what the deal is with short vs long shaft outboards. When do you want one vs the other? WHY do you want one vs the other? I would have thought all small boats (like a Valco or Sears Gamefisher) would need short shafts and you'd use a long shaft as, I dunno, a kicker on a sailboat or something? But then as I've been looking for a little fishing boat, people seem to advertise all sorts of stuff with those little boats.

Is that just a case of being idiots and not using the right engine? Or do some smaller boats use long shafts and some short and it's all about transom height? Does it make that much of a difference?

 

[SSPey]

 

[Shaker Jake]

Short shaft means motor is built to hang on a 16” high transom. Long shaft designed for 20” transom. Put a short shaft motor on a 20” transom and the propeller does not extend deep enough. Put a long shaft motor on a 16” transom and the prop is too deep.

Doesnt matter much if you only troll. But huge difference if you try to get the boat on plane. Repeat- Huge difference.

 

[PhilR]

What about putting an OB on a drift boat, where the bottom of the transom is pretty high compared to your average boat?

 

[Grayone]

On a driftboat the ob is mounted a long ways from the bottom and gets plenty of flow. But, no matter what, you need enough shaft to get the prop into the water.

 

[headduck]

On our boat the main is long shaft and kicker extra long shaft.

For me all, about relationship of cavitation plate to bottom of hull... mounting height, transom depth etc.

 

[SurfnFish]

What about putting an OB on a drift boat, where the bottom of the transom is pretty high compared to your average boat?

XL shafts for drift boats almost always the call...hp less important, as the hull speed is limited by bottom rocker...that same rocker that allows a DB to plow through white water safely and manuever with oars turns into a non-planing plow in flat water under power.