[altonhs]

I have a 1998 mercury 90 outboard that will not turn off unless I disconnect the fuel line. I have replaced the ignition key switch but it will still not cut off. Any help would be much appreciated. The kill switch does not turn off the motor either.

[jmburock]

Sounds like bad kill switch. Could also be wired wrong at the ignition. Check Black/yellow wire path from the ignition on out to the mercury tilt switch to the switch box. Any short in this black/ yellow wire could result in your condition.

[JUSTINTIME]

Originally Posted by altonhs

I have a 1998 mercury 90 outboard that will not turn off unless I disconnect the fuel line. I have replaced the ignition key switch but it will still not cut off. Any help would be much appreciated. The kill switch does not turn off the motor either.

try finding the black/yellow wire, unplug it from switch-box
start motor, now touch that wire to the engine, it should shut off, if not u have a bad box
if it does, u got a bad key switch or wiring