I very recently bought Coleman 400A Backpacker stove off epay I have tried one of the tricks for cleaning the tube that goes over the flame and that seems to have worked quite well in that it now delivers fuel to the burner head. Pic of flame and stove on the go The issue that I have is that it wants to let fuel into the pump tube when I pump to add pressure to the stove, which is a recipe for disaster if you need to pump when its lit. Plus it washes the oil off the pump cup. Can you still buy the part at the bottom off the tube? Is it broken? Bit of advice required.