I have s 5211 that has been difficult to start. During the investigation of the problem we discovered that we are only getting fuel to the rear cylinder. The front two are not getting fuel at all. Tractor has been very useful as it is equipped with a front loader but has not been used as much lately. Not sure if there is something stuck or broken in the injector pump but cant figure out why Im not getting fuel to the front two cylinders. Any help would be greatly appreciated