motor will not stop

[woodworker]

some times motor keeps running after key is turned off and kill switch pulled.
This is a 2004 9.9 Mercury ser.# OT851354

[boats.net]

Could be broken Black/Yellow wire inside main harness between engine and key switch, or a bad key switch. Disconnect main harness from engine and key switch and check for continuity on black/yellow wire in main harness to see if its a open circuit .