I have a John Deere Z915B z mower. Sometimes it will start and sometimes not! Seems like it starts most often when cold and not so much when hot. We know it is an ignition issue because we can hot wire it with a long screw driver. We took it in to the JD place it was purchased, the kept it 8 weeks and basically did not listen that it was a ignition issue and replaced the starter, and, of course, the ignition issues remain! Has anyone else had this issue? Any suggestions? Thanks in advance.... Susan