You were were probably taught how to siphon fuel from your motorcycle tank during primary school science class. Perhaps not in such exact terms, but you no doubt would have learned about siphoning and the magic of fluid mechanics. While you can buy (and we’d recommend you do) specialized siphon pumps, you can also go full MacGyver and take fuel from your motorcycle tank with just your mouth and a piece of flexible tube.
In technical terms (courtesy of Wikipedia), siphoning refers specifically to a tube in an inverted ‘U’ shape which causes a liquid to flow upward above the surface of a reservoir, with no pump but powered by the fall of the liquid as it flows down the tube under the pull of gravity, and discharging at a level lower than the surface of the reservoir whence it came. Note that while the siphon intake tube must be below the surface of the liquid in the higher reservoir, it need not touch the liquid in the lower reservoir and indeed there need not be a lower reservoir; a siphon can discharge into mid-air so long as the exit is below the surface of the upper reservoir.
A siphon hand pump is the better way to go because you’ll minimize your exposure to fuel vapors. Cheap ones cost around $5 and will be more than adequate for most people’s needs. However, if you’re extraordinarily cheap or are out on the road and don’t have access to specialized equipment, follow these simple steps.
Inset your flexible tube into your tank. A transparent tube is best so you can see the fuel inside of it. Ensure that the end of the tube is submerged in the fuel.
Ensure the bottom of the tube sits beneath the tank, while the top of the tube is positioned above the tank.
Suck on the other end of the tube and watch as the fuel comes out of the tank and rests at the bottom of the ‘U’. Don’t suck too hard or you will enjoy the taste of fuel in your mouth.
Place your thumb on the end of the tube, sealing it.
Lower the tube into your container which ideally should be resting on the ground to earth it. Release your thumb and the fuel will pour into the container.
When you’re container is nearly full, pick it up with the tube still in it and raise it above your fuel tank, stopping the siphon. Alternatively, remove the end of the tube that’s submerged in the tank.
Make sure you thoroughly wash the tube (or replace it) before using it again.