Advantage/disadvantage of a long shaft on a 15"

[Sitkaspruce]

I have a 12' tinny with a 15" transom and will be putting either an 8 or 9.9 on her. I also want the engine for a larger boat down the road as a kicker so do not really want a short shaft.

Is there any advantage/disadvantages to running a 20" long shaft on a 15" transom??

Cheers

SS

 

[SteelyDan]

No advantage. Build up your transom the extra 5" if you go with a 20" shaft

 

[tubber]

Take off the existing plywood if that's what you have, make a new sandwich with plywood on the inside and outside and 5 inches of whatever thickness in between the two bigger pieces to rest on the top of your transom. Make it fit your existing fastener holes. I did this for years till I could afford to keep the long shaft on the big boat and buy a different 15" outboard for the small boat.

Won't be a problem. If you don't lift the motor, you'll likely get spray coming over the transom down your crack.

 

[Sitkaspruce]

Thanks guys!!

So what is the disadvantage of leaving the transom at 15" and running a 20" long shaft?? I don't want to remove/modify the existing transom.

Cheers

SS

 

[Franko Manini]

You will get a huge spray coming between the shaft and the transom at speed. You will also lose speed due to increased drag. If you can deal with that, or just want to go slow, then there isn't any real issue.


Franko

MILF (Man, I Love Fishing)

 

[7Deuce]

I briefly had a 14 foot tin boat with a 20" motor on a 15" transom. I would highly NOT recommend this. It always felt like I was cruising with the parking brake on. I quickly built up the transom and would never go that route again. Either way, good luck with the project and let us know your experience