| Hi Meli:
I have a running John Deere tractor that I am going to refurbish. When it is cranking over at start up I hear what seems like a loud knock. I don't hear it while it is running but do hear it again at shut off. What may it be? I plan on rebuilding the engine so I guess it will eventually be taken care of. It would be nice to have an idea as to what it could be so that I can prepare.