I had the same problem with mine as did my friend with his. We both have walbro pumps. The problem he had was that the filter bag that comes with the walbro pump is shorter than the original, so when his tank got low it did'nt pick up as good, so when going around corners he had the same problem as you. When i fitted my new pump i put the original filter back on and never had the problem that you did until a few months down the line. When i investigated i found that i had not put on the securing washer that holds the filter bag to the pump and it had come off inside the tank causing me the same problem.