Long Shaft Vs Short Shaft

[Growbug]

There are only a couple of forums where you could expect a thread title like that!!!!

OK.. My 'big boat' has a transom of 19" (long shaft), my little boat has a transom of 15" (short shaft).

What problems, if any, would i get using a 5hp kicker from the large boat as a main for the small (rated 7.5hpmax)?

 

[Thuggin4Life]

The only thing you will get out of doing thisa as far as i know is having a way deeper prop than needed. If it works for you then i say do it.

 

[Growbug]

yeah, the two problem i see is weight and deep prop. I have no idea if a deep prop is a negative. Well.. it would be in shallow water, but.

 

[Hawk]

:lol::lol::lol:

The long shaft should work ok on the small boat. In shallow water, tilt the motor (to the shallow water position). Sometimes a short shaft motor sucks air in the shallow water position.

 

[GDBrown]

Watch out for Over-steer!

Watch out for Over-steer!

You probably won't have any problems with that low of HP. If you were talking about 10 or 15HP then you start having problems controlling the boat in higher speed turns. It acts kind of like over-steer on a car if you are familiar with that. You start the turn and it just wants to turn faster and tighter! It can be quite frightening the first time it happens when you are up on plane. I had that happen when I switched from a 9HP short shaft to15HP long shaft on my 14ft Starcraft! I ended up making a new transom that was 20 inches to solve the problem.

GD

 

[Growbug]

I was thinking that may be the problem.... just like trying to power around a corner with the old rear wheel drives. Spent a few moments in my past wondering why i was sat on wrong side of the road, facing the wrong direction..
Yup.. came across an old thread on another forum about raising the transom by a few inches with boards and C Clamps. I should be able to do something.

Thanks for the comments.

 

[stream2.5]

if the small boat will plane off you will also encounter slight spray comming back into the boat off the front of the motor. but on a 5 hp i doubt you will have a fast enough hull to cause any noticable effects other than ugly over long motor... but really only a few people who arein the know will notice that its a hair to long..