Long or short shaft outboard

[Ghost6ix]

I have a 1980 mercury 40hp outboard and was trying to figure out if it is a long or short shaft outboard,where would you measure from?I measured from the bottom of the power head to about the middle of the propeller shaft and it was about 25 inches...any help would be great...thanx

 

[Wee Hooker]

Re: Long or short shaft outboard

Measure from the top of your transom/inside of your mounting bracket where it rests on the transom to the cavitation plate just over the prop. If it's short, it should be 15-17" or so ( designed for a 15" transom.). If it's long, it will be 21-23" or so designed ofr a 20" transom. The goal is to get that cavitation plate just under the surface.
hth

 

[Barnacle_Bill]

Re: Long or short shaft outboard

You want the cavitation plate even with the bottom of the boat.