Kawasaki Mule 600 charging system.


A neighbor has been pestering me over his Mule not starting lately. He replaced the battery a few months back, then I replaced the starter a month or so after that. It's been starting fine ever since until just last week. I've been over there two or three times since and this is what I found.

The battery is dead. It's hardly old enough to be defective, but who knows. It will start if the battery is charged, but won't start on its own after that. First thing I checked was the charge rate. It's charging at 13 volts while running. Seems a bit low to me, but I know many Ford tractors that run for years at 13 to 13.2 volts without issue. Maybe this ATV battery (whatever style it's called) won't survive at that rate of charge? I don't know the answer to that. I checked for a voltage draw when it's not running and concluded there is none. He was able to replace the battery under warranty a day or so ago so the current battery is new. He followed whatever instructions came with it, charging for so many hours, etc, put it in and and it was okay for the the first day or so. Now it's dead again. I guess I will go back tomorrow and look at it again. I can only assume at this point that the charge rate is too low to sustain the battery. If that's the case, then what's the most likely cause for that? The voltage regulator?

I'm not an ATV guy, and don't fool much with air cooled engines of any kind so I'm not sure where to go with this.


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In my experience, more often than not, it was an issue with the starter solenoid.
Also check the machine for more than one solenoid. My ZTR was having all kinds of issues. There's a solenoid on the side of the starter but tracing the wires, there was another solenoid (the one that was bad) in-line.

Tons of articles to research. Here's one.


I'm back out there today. Battery was on the charger again. The man thinks he was partly to blame because it's hard to get the charger leads onto the battery and he thinks the connections may have not provided a positive result for the hours of charging he did supposedly following the directions that came with the battery. Okay, that said, the machine started right up for us today. I backed it out of the dark shed it was parked in and started looking at things again. It was charging at 14.4 14.5 according to two different meters I tried today. Nothing like the 13 volts I saw when I was there a few days ago. All seemed well today. It started without hesitation four or five times, no problems. This time I added a wire to the positive post of the battery and zip tied it to something near the front of the bed. Its stripped back far enough that he can clamp the charger lead onto it without issue should he need to. It's got a shield covering the bare copper he can slide back when needed. What I saw today makes me think he probably will be okay now. Time will tell.