Just finished reassembly after replacing piston rings and valve seals and turn it over to find it fire right up. Running smooth for a couple minutes and I turn it off. Go to restart just a minute later and the display is flashing FUEL. I've never seen this message before??? but realize the tank is on Empty so I fill it up. Then when I go to restart it just sputters and only runs as long as my foot is on the gas. Try to restart again and now it won't even sputter. Tried several times and nothing. Any thoughts PLEASE! thanks