On rare occasions while tilting my 91 merc up (using the switch on the motor) the switch would seem to get stuck and keep raising the motor. The other day out of nowhere while coming back to the marina my motor began to tilt up all by itself. Luckily I caught it in time before frying my impellar. I assume the switch on the motor was the culprit. Does anyone know how easy it is to replace it? Is there anything else i should check that may have caused this to happen?