Recently I was bush hogging and my Kubota just lost power all of a sudden. Managed to get back to the house but very slowly. Changed the fuel filter and bled the lines and now it will not crank at all. When I bled the lines the fuel did bubble out the top so does that mean my fuel filter is working? Also there are two valves that I don't know what they are. There is one down near the fuel pump and the other is near the top and goes back to the fuel tank I believe. Should they be open or closed?