I have a 1992 sears 14.5 hp B&S motor lawn tractor that will not start by key but will by jumping the solenoid. I have replaced the solenoid and ignition switch. After the new solenoid was installed the tractor will at least turn off but still will not start. This tractor has a brake switch that is broken, a mower switch and seat switch. I'm not sure if I can jumper the switches to make it start. The problem seems to lie in the wiring or switches. Any ideas let me know.

Replace the broken switch. And be sure the solenoid is grounding well.

Thank you mowerman, as this tractor was given to me with little history I was not sure what I was looking for. I found the problem to be burnt wiring. After re-wiring the tractor it now starts with no problems.