Re: 1975? Chrysler 25hp ( 254BA)
That's electric start, magneto ignition with aux. pull start cord. If you prime it and pull the cord, it will (or should) start.
Now: To wire it, you attach the red end battery wire to the POS terminal and black to NEG. When you get an ignition switch, you wire yellow to the "S" terminal, Green to the "C" terminal and the blue and white to the "M: terminals. In your third photo, blue and white attach to the squared spade terminals that connect the wires up under the flywheel. These short the points and stop the engine. Green attaches to the choke wire and yellow attaches to the start.
There is an interlock on both the electric and pull starter so that the engine can not be started in gear.---it must be in neutral.
You will need to buy a black multi wire cable, a standard six terminal switch, a control box, and cables. Look for them all on ebay.
However, for test purposes, you will be able to pull start the engine.
