We've done. Drained tank & used fresh diesel, all filters have been replaced. Just used the injector cleaner...filled bowl & ran. Helped a LOT. It runs fine, just bogs when we tried backhoe-- which is hydraulic, not PTO. SoLook in tank for any trash floating around or water in the tank, check fuel/water separator filters for any water there by draining the petcock on it, if not next will be change the filters themselves and get ready for a a fight to prime them if not electric fuel system. If not there then last resort is injectors.