Did you check the little electric lift pumpIJ I went thru two of them this fall. They would pump okay till they got hot and then they would start to fail. once I changed pumps it was cured. I also think the B-2 biodesiel I switched to had something to do with it. I changed fuel filters on every tractor,combine and fuel tank I have three times this fall. Good luck I would love to come down to Oz and help but I have to go to Nebraska to learn about Center Pivots later, Will