John Deere single piston engine

[ajamwant]

I have a John Deere tractor d120. The engine stopped. I was probably low on oil. I took a look at the valves. They seem OK. The piston moves up and down. The problem is that the connecting rods to the valves done move. Any suggestion what to do
?

 

[Scrubcadet10]

What you're talking about is the push rods,
What make engine is it? Model number?
If the push rods aren't moving, most likely a cam shaft issue.