General Starter question

Have a general starter question, non Mopar but a good head scratcher. This starter, on a John Deere mower, seems to NOT work about 70% of the time when you hit the key. The other 30% of the time it engauges, turns the engine over, and it fires up. The 70% of the time it doesn't work, makes the general solenoid "clunk" and doesn't turn over. If I take the starter off and leave it wired up, turns over everytime off the key. Or if I leave it bolted up to the engine, and run a jumper wire to where the key sends power it'll turn over everytime. I get 12.05 volts to the starter when I use the jumper, 11.95 when it goes through the key circuit. What is going on here?????

Maybe you have shorted windings? If you check it for excessive amperage draw you may find your problem

I believe you found the problem. You say you jumper "to where the key sends power" to the solenoid and it turns over. Let's be clear--you are jumpering to the SMALL terminal on the solenoid?

Can you post a link to the wiring diagram? This may well have a relationship with the vast horrid maze of safety switches on these rigs. There may be enough voltage drop in the deck/ seat/ accessory/ etc/ etc/ etc safety switches that is causing a drop.

Sounds to me like there's nothing wrong with the starter or solenoid

Probally a Kohler motor.My Allis Chalmers did the same thing.It was the starter.It came apart in pieces.Take a test light and with the starter installed check the hot wire to it.If it has power and dosent crank its the starter.Its probally the simplest system in the world.I bought a new starter from the bay for like 60 bucks.Just have to know the HP and style.There were pretty much 2 or 3 styles of starters.Rocky

You might need to be a little clearer there TheRocks. Someone might consider the main power from the battery as the starter "having power". Isn't what you mean to tell him the wire that engaes the solonid should show voltage when you attempt to crank it? Something that simple could be a bad relay (it it's set up like that)