Small Engines (Lawn Mowers, etc.): Sears model 917.273070 Riding mower, safety switches, control seat

Question
I have a sears riding mower model 917.273070 with two problems.  When you try and start it it will only make a load clicking sound which i think is coming from the solenoid.  I can jump across the solenoid and it will start and run just fine.  Should I replace that or is there something else I should try first.  Also when I go to engage the PTO switch (which is new) it won't turn on but if you leave the switch in the on position and get off the seat the safety will stop the engine.  Bad switch or should i look somewhere else for the problem?

Answer
It sounds like you have a safety interlock problem.  when you turn the key to the start position the current has to travel all the way through the the safety switches on the brake, neutral control, seat to the solenoid, then to the starter.  

You need to find your defective safety switch.

The seat switch is working properly  its supposed to shut off the blades and the engine should you fall off the tractor.

Electrical problems can drive you crazy, but you will have a feeling of self confidence once you find it and repair it.