Small Engines (Lawn Mowers, etc.): JD 116 H mower PTO cutoff, lawn tractors, high grass

Question
After several hours of mowing, my pto for my mower will cut off ,usually in high grass (driving very slow and no bogging down), with my engine still running..Switching the PTO on and off at this point gets no response even when I move it to clear ground..If I cut the tractor engine off the engine will not crank (dead battery)..(Sometimes the battery will drain overnight while parked..) This seems to be  an intermittent problem..but eventually the battery will end up not holding a charge..If I get a new battery it will run for several times with no problem  then the PTO cuts out and it won't start..Do I have several problems going on here?

Answer
You appear to have a charging problem.  The engine isn't dependant on battery voltage to run, with the exception of the anti-backfire solenoid if you have one, but the PTO is and of course the starting system.  

You may have a seperate problem with the battery draining, but it may also point you to the key switch.  If your charging system goes through the switch, and the battery runs down overnight, then a new switch might be the solution.

You'll need a multimeter to find the exact problem.  I'd start by testing the battery voltage both with the key off and with the engine running.  There should be a jump of 1-2 volts when running.  If there's not, then you know there's a charging problem.

Unfortunately in this sort of forum I'm limited in helping you through this one.  Finding the exact trouble may be difficult, but I would start with the voltage test and then checking all connections for continuity.  You'll need a service manual for your specific engine to tell you what values to look for in the stator and the rest of the charging system.  There's not really any good service manuals available that detail the electrical system of lawn tractors, but JD should be able to supply a schematic if you're not familiar with them.

Thanks, PK.