Re: omc 120 has no spark
The deadman switch/ignition cutoff should be between the ignition key and the steering column. It looks sort of like the top of an "AA" battery. The center pin must be pressed in and held by a clip in order to get power to the ignition. If the clip is missing or becomes unseated, the engine will not fire or, if running, shut down. You can crank all day if the switch is not properly locked down.
I spent 20 minutes trying to figure out why my boat wouldn't fire before I realized the clip had become unseated. Put it back on correctly and the engine fired right up.
The clip is supposed to be connected to a lanyard that the captain clips to their lifevest/belt clip, etc and is designed to shut the engine down if you are not in a position to control the boat (go overboard, bounced out of your seat and away from controls, etc). It is a real safety device and SHOULD NOT be fixed with a work around.
If you find out you lost or don't have the clip, you should be able find replacements at West Marine or some other marine supplier or marina.