You did read about the safety lanyard in an earlier post, right? I've had one of those switches fail in the past as opposed to the lanyard being pulled.
Edit - on second thought the lanyard would allow the boat to turn over but not start.....
'97 Prostar 190 - LT-1
Prior boats - 2009 X14, 2008 X14, 2005 197, 1988 Tristar 190, 1989 Prostar.