You must have some wires connected to the distributor. It can't run without them. What kind of distributor is in it? The old OMC Prestolite or newer Merc Thuderbolt? How the timing is controlled depends on what ignition system you have.
The shift interrupt system ties into the ignition system and you will need to reconnect it somehow. OMC did it with two switchs and a ESA Module and Merc does it with just one switch. Maybe you could post a picture of your engine to help identify what you have.
Dave