Here's the wiring for the 3 cylinder disregard all other wires on your motor as Nordin said; it is set up for a four cylinderCheck out Master Tech Marine, they have wiring diagram for 4 cylinder Force with Prestolite ignition system.
Your engine has 3 cylinder but the wiring is the same except for one cylinder less.
BTW Your engine has an ignition mounting plate from a 4 cylinder engine.
Pre owner might been messing with it.
My guess......random parts thrown on to sell as "complete"I'd like to know the story behind those changes???
Got it as a deal with a boat and trailer for $1000, along with another parts motor that has no compression on one cylinder.My guess......random parts thrown on to sell as "complete"