I have a 2001 model JD riding mower with a Kohler 15 HP motor. It has a problem with the starter, and I would like some help diagnosing it. Here is the issue: When I start the mower, sometimes the starter keeps on running even after the mower starts. It disengages the flywheel, but continues to spin even after I stop the ignition. It will keep on spinning until the battery runs down, and that is the only way to get it to stop. Usually if the mower runs for any length of time (ten minutes or so) the starter will stop spinning. I only noticed this problem when I forgot to choke the motor once before turning the ignition key, so the mower cranked but didn't start - and then when I turned the key off the engine stopped turning over (starter disengaged) but the starter kept spinning. Turning the key off did not stop it from spinning, and turning it back to start did NOT reengage the starter... like I said it keeps going until the battery dies. My initial feeling is that the problem is something electrical. I know the battery is pretty weak, so I thought I would start with replacing that, but should I also replace the solenoid? What about the starter, could it be bad? Are there any quick tests I can do on it while I have it all apart? Thanks very much.