Re: 1971 mercury 1150
Quad is not exactly correct on his description of the ign system. That motor has a battery powered CDI ignition with a distributor. To hot wire it, you would need to connect two battery cables from the battery + post to the pos side of the starter solenoid, and from battery neg post to the frame. Run a jumper wire from the pos side of the starter solenoid to the red wire on the switchbox. Run a jumper wire from the red wire on the switchbox to the white wire next to it on the switchbox. The white wire needs +12VDC in order to produce spark. Now momentarily jumper the yellow wire on the starter solenoid to the red battery cable ont he starter solenoid, and she will crank. Add some choke (pull up on manual choke know), and she may start. Disconnect the jumper to the white wire to stop motor, should it start to run.