Have 7 yr old Troy-Bilt 17.5 hp riding mower that will not turn over. Battery and cables OK Starter wiring tight and OK. Thinking safety switch somewhere is bad on pto or something. Have no wiring diagram.Can anyone help me find these or other answers to problem. Also had ignition checked and is OK. Thanks.
Billy

Does starter relay pull in but won't start? Relay gets pitted contacts sometime. WD40 helps.
Put a 12 volt jumper to the relay to see if it feeds the starter. If not go find the open connection.

I don't see a mention of a solenoid here which can cause the problem here. Use a screw driver to jump the post with the ignition key on and see if the starter turns jumping the solenoid. If so it's a bad solenoid.

Hi,
I believe what was referred to as te "relay" was in truth the solenoid.
The most reliable test of a solenoid, one with two large posts and one trigger, is to jump from the "hot" (battery side) of the solenoid to the trigger with a 14 ga. Wire.
Why, you ask! Well, it tells you more that one thing. If you jump it and it works, then it is not the solenoid but power reaching the solenoid. If it does not replace the solenoid. Both dependent on a known good battery and voltage reaching solenoid.
If it has four posts, two large and two small, then the ground is supplied externally and must be checked to exist first (Deere, Toro, etc.) have been known to put safety swiches in this ground circuit.
Oh, you can get a copy of the manual from MTD by copying the model and serial numbers down (and letters) and going to their site. All schematic for model covered by that manual are toward the rear after other parts breakdowns.
Peace,
Clarke