Rookie Fuel Line Qs.

[zelek]

Would someone explain how, in a nutshell, the fuel system works on a smaller 2 stroke outboard with a portable fuel tank??

I've made some rookie mistakes in my first year owning a boat and I'm still not real clear on everything.

After switching from a plastic to a metal tank I learned, the hard way, that I have to manually open the vent on the metal tank. Hmm..never had to do that with the old plastic one cause it vented through the fitting where it attaches to the tank. Another time I learned to double check the fuel line and make sure it "clicked" in place so it doesn't slip off the fitting.

Each instance resulted in starving the outboard of fuel.

So what role does the fuel pump, primer bulb and the need for air in the tank all play as the fuel travels down the line??

[danfall]

The fuel pump creates suction, but only with fuel, not air. Thus, the need for the primer bulb; it sends fuel to the pump which in turn will pull fuel, with one catch. It can't pull fuel against a vacuum stronger than the one it creates, thus the need for a relief valve in the tank.

Some older tanks worked differently, they primed at the tank and had no venting. I'm not quite sure about these, but expect they are much the same.