Logo

Shaft length question.

ifisherman

New member
Howdy all. I have a 2005 Carolina Skiff J14. The transom measured 16". It currently has a 15hp Honda and the shaft measures 17 inches. I might upgrade the motor to a new one and use the old 15 on a friends boat.

Question is I see only 15" or 20" shaft options. Am I measuring my outboard correct at 17" from transom mount bracket to the keel just above the prop? I don't see any new motors with a 17" shaft.

If my transom measures 16" I am thinking a short shaft is the way to go. But at 15 inches of shaft length that would put the keel above the prop at about a half inch above the bottom of the boat. Is this good?

Thanks. I appreciate the help.
 
The anti-cavitation plate, which sits right above the prop (which I assume you are calling the keel) should be even with the lowest part of the hull at the transom.
 
A 16" transom takes a short shaft ( 15" ) motor.-----Folks are often confused about what the " shaft length " is and how it is to be measured on a motor.
 
The anti-cavitation plate, which sits right above the prop (which I assume you are calling the keel) should be even with the lowest part of the hull at the transom.


Yes yes, anti-cavitation plate. No idea why I was calling it a keel. Anyway thank you for the responses. I ended up ordering a short shaft 20hp with a 15" shaft. From my measurements the ACP will be about 1/2 inch above the bottom of the boat. I have had enough responses saying the 15" shaft is the right motor so good to go.

Do you all think that 1/2 inch is a concern? Before I go bolting it onto the boat should I shave down the transom a bit to get the ACP perfectly even or am I going way over board on this one?

Thanks again everyone.
 
It's a performance issue. The closer the anti-cavitation plate is to the bottom of the transom the better performance you'll get. You could install a manual jack plate on your transom which would allow you to move the motor up and down. Alternatively, you can install a hydraulic or electric jack plate which will an infinite number of settings and allows you to run in very shallow water. Below is a link to one of many that are out there...

http://www.vancemfg.com/product-p/j...FNWHAnguoHGggib6mA6kYl4G2W42UZQhoCCokQAvD_BwE
 
Well, someone was kind enough to send a PM and correct me on my terminology. I've always called the plate on an outboard that sits above the prop as an anti-cavitation plate. But I have been correctly informed that it's properly called an anti-ventilation plate.
 
Well, someone was kind enough to send a PM and correct me on my terminology. I've always called the plate on an outboard that sits above the prop as an anti-cavitation plate. But I have been correctly informed that it's properly called an anti-ventilation plate.


Funny. I have heard Anti-Cavitation plate. Never heard ventilation. I am no expert on the topic that is for sure. Maybe I will stick with that part that sticks out just above the prop.

:)
 
Do you all think that 1/2 inch is a concern?

Nope, it shouldn't be,.... 'n it might be ever so slightly Faster,.....

A potential draw-back could be if ya get prop blow-out when turnin',.... possible, but unlikely as it is,....
 
Back
Top