1977 Evinrude 115 HP where to start?

[Chevy57]

Good morning,

I have Always been a big fan of the old school speed boats. I grew up on the St. Lawrence River near alexandria bay Ny. I just picked up my first boat of this type. It’s a 78 checkmate predictor with a 1977 evinrude 115. I haven’t tried to start it yet. The folks I bought it from say it runs great. I know, no one has ever heard that before when buying an old boat. It needs some love but I would like to get it running and see how it goes. I am a car guy and I’ve had several boats but no outboards. My last boat was a 2003 sonic prowler. So where can I go to start learning about these old outboards?
is there anything I should do before I try to run this motor?
can I run it on muffs or should I put it in a barrel?
i was thinking of pulling the lower unit apart and checking the impeller and just having a look around.
i have a bore scope so I’ll pull the plugs and have a look inside the cylinders.
what is the proper way to check compression on an outboard?
I have a leak down tester too, but never really understood how to use it
I'm excited to get this boat on the water

thanks

[racer]

Personally I would start by locating an original factory service manual, I have seen them on E-bay.