First Gator, first JD!

Hello,

I recently purchased 3 Gators. 2 don't run (suspected starters) and one needs choke feathered to stay running. Now, it hasn't been over 16 degrees since I got them, but anyways... A few questions, I can't seem to find my SN on any of the links/tools I have found. Will someone advise on model/year for the following SN:

MOHXOPBO81647
MOHXOPBO81649
MOHXOPBO81656

In addition, any suggestions on where to start troubleshooting prior to running to a JD maintenance shop?

Thanks in advance!