shaft length?

[Dawgs]

how do i determine what length shaft motor i need for my boat? where do i measure? i was told to measure from the top of the transom to the bottom of the hull. is this true? i measure and its about 21-22.

when mounting the motor...what part of the motor should be even with the bottom of the hull?

 

[F_R]

Re: shaft length?

That is a long shaft. Generally referred to as 20". Yeah I know, it really is longer than 20".

The flat anti-caviataion plate above the prop shoud be about even with the boat bottom or slightly lower. No hard and fast rule on this though. It "depends".

 

[Dawgs]

Re: shaft length?

how long is a "short" shaft?

 

[JB]

Re: shaft length?

A "short" shaft is 15", Dawgs.

One correction on the measurement. Measure from the top of the transom vertically to a point level with the keel. That is usually an inch or more less than measurement on the surface of the transom.

On the plate (anti-ventilation plate is correct, though it is usually called a cavitation or anti-cavitation plate) start with it even with the keel and move it up one hole at a time until you get prop ventilation in hard turns, then drop it down one hole. That will usually end up about an inch above the keel level.

 

[Dawgs]

Re: shaft length?

ok so i measure 21 or 22.....im looking at a 20 shaft?

 

[samo_ott]

Re: shaft length?

If you measure it JB's way vertically, do you get close to 20"?

 

[Dawgs]

Re: shaft length?

im not sure what you mean by the keel

 

[JB]

Re: shaft length?

Bottom of the boat, Dawgs. Lowest point.

 

[F_R]

Re: shaft length?

Just don't fret about it Dawg. You have a long shaft (20"). If it were anything else your measurements would be Way off.

But if you want to re-measure, lay a straight board or somethng along the bottom, then measure straight down from the transom top to the board, vertically, not along the transom. It'll come out somewhere around 20-21" in most cases.