Originally Posted by 40 to 332

I used a Gastapper twice and on both occasions was able to get past the screen (or ball valve) and siphon out about 40 liters from a full tank with no problems. After that, it was siphoning a mixture of air and gas so there was no point in continuing. I used the smallest diameter siphon tube that comes with the kit. I could feel it ease past the screen as I fed it down the neck of the gas filler tube.