I have a 1978 Johnson 115. My lower end unit went out and I had a mechanic take out the old lower unit. I bought a used 1979 Johnson 100 hp lower unit that is in working order, but do not know how to install it. First of all, are these parts compatible? Is it a fairly simple procedure, or should I hire it done? I'd like to get it done this week for the weekend. Getting a mechanic might be difficult at this point with those time constraints. Can anyone assist or direct me to a site that could give me a diagram?
