"Curly" wrote in message
om...
My friend just got a boat with a 1989 Johnson 70hp outboard and we
don't know what the black knob on the control box is for. The knob is
just below the ignition and turns in both directions. It doesn't seem
to tighten or loosen, it just turns easily in both directions. Does
anybody know what this knob is for?

Thanks

Could be a kill switch. My 200 has it in that position.
Does it have a hole through it, or a clip on the end?