I just got a 1975 runabout with a mercury 850. the ignition switch is bad. Is it possible to hotwire the ignition so I can make sure the motor is good before putting any money into it?
Why not just get a cheap switch for a riding mower and use that for the test. It would be worth the investment as insurance. If you hotwire it wrong you may burn something up and it may not work or do damage.
rlatta, If that motor has a distributor, run a jumper wire from the red wire on the switch box to the white wire on the switchbox (adjacent terminal, starboard side of motor). If it is distributorless, I do not know off hand how to hot wire. Likely you will need to disconnect the wire that grounds the ignition.
Why not just get a cheap switch for a riding mower and use that for the test. It would be worth the investment as insurance. If you hotwire it wrong you may burn something up and it may not work or do damage.