I have a 5211 with a fuel problem. Replaced filters. Blew out lines etc. then we discovered that we are only getting fuel to the rear cylinder. Nothing at all to the front two. This tractor has been very helpful with projects in the past as it is equipped with a front loader but with the big projects done it has not been used as much lately. Not sure if something is broken or stuck in the injector pump could use some advice on the issue so I am not fixing things that arent broken