Boat shaft to boat

buda

Seaman
Joined
May 6, 2008
Messages
51
Does anybody know the size of shaft you use on a boat. I have a 25'' shaft on a 19' Trophy Bayliner [1989}. Can you use a 20'' shaft outboard. I'm thinging of changing motors and i did'nt know.

Thanks Buda
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: Boat shaft to boat

Measure the vertical drop from the top of the transom to a point level with the keel (bottom of the hull). That is about the shaft length you need.

A 20" shaft motor on a 25" transom would be junk very quickly because it wouldn't get cooling water.
 

buda

Seaman
Joined
May 6, 2008
Messages
51
Re: Boat shaft to boat

I don't know if i made myself clear. I have a Force 125 HP on a 1989 19' Bayliner boat. The drive shaft on the Force is 25''. Can you use a outboard motor with a 20'' shaft on that boat.
Thanks Buda
 

frankie g

Petty Officer 1st Class
Joined
Nov 14, 2007
Messages
388
Re: Boat shaft to boat

he did ! measure and you'll have your answer.....Probably not though
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: Boat shaft to boat

You might have an extra long shaft motor on your B'liner now, Buda, but you don't KNOW that it is the right length for that boat.

Measure the transom and use only engines that fit. If your transom is 25" (extra long) a long (20") shaft engine would quickly burn up.
 

buda

Seaman
Joined
May 6, 2008
Messages
51
Re: Boat shaft to boat

I did go out and measured it. It measured 25'' I'm the one who did'nt know what he was doing.

Thanks everybody
Buda
 
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