Have had the same problem, disonnect at fuel filter and at tank blow with air both directions than plug tank side (don't hook it back up). fill fuel line full of petrol let set for a short while and then blow through with air again. I personally wouldn't recommend putting water in the fuel tank, but while your line is still off put a little fuel in the tank and put a rag around your airline push all of this into the fuel filler and blow out with air (the fuel line should still be disconnected) repeat several times than reunite the fuel line with tank and install a new fuel filter and should be off and running. If the line plugs up again you will need a major fuel tank service, which involves removing the tank.