how do you measure lower unit merc 225 efi

General Boats and Motors
1

i have a 31 fountain with merc 225 efi’s .i have one lower unit i need to replace .how do i measure .or how do o know what size shaft i have .im thinking 25" not for sure ,thanks for yall’s help

2

I’ve been told to measure from the (roughly) bottom of the block to the cavitation plate and you will get a good idea of shaft length.