John Deere 111 starting problem

My John Deere 111 is older than I am and I've had to do a lot of work on it but I'm far from an expert. The last time I used the mower it stopped running and I thought it was the battery so I charged it. Now when I go to start the thing, I hear a single click and that's it. I took off the starter cover and the plastic gear is fine. What should I try next?



Thanks for your help!



Matt