merc 115 OB, is it a short or long shaft?

[h2oTherapy]

I have heard the terms "short" and "long" shaft/housing refering to lower unit drive shafts. How would I determine which my 1990 115 merc is? Is there a place where I can take a measurement, and if so where.

 

[wilde1j]

Re: merc 115 OB, is it a short or long shaft?

Top of cavitation plate to inside bottom of mtg bracket (part that sits on top of transom. Stds are 15, 20 , 25 and 30" Used to be 15= short and 20=long, but that obviously doesn't fly now.