Try watching this video on replacing chainsaw fuel lines:
http://www.YouTube.com/watch?v=JrXpU70Hmi0
bad seal in between your intke manifold and carburetor
The location of the fuel filter depends on where the carburetor is mounted. If the carburetor is mounted directly atop the fuel tank, the filter is located within the tank at the end of the hose that attaches to the carburetor. The carburetor has to be removed to access the fuel filter. If the carburetor is not mounted to the fuel tank and the fuel is "gravity-fed" to the carburetor, the filter is usually an in-line filter located somewhere on the fuel line between the tank and the carburetor.
Throttle body injected. Like a cross between carburetor and injector.
The process will vary between models. The lines should be fit into the tank tightly, with no gaskets. There may be an internal filter in the tank, it plugs on the end of the suction line. The other ends of the lines slide tightly onto the carburetor fittings.
a single replacement has one product and the double replacement has two products.
The position of the fuel filter depends on what type of fuel tank to carburetor system your mower uses. If the carburetor is mounted directly on the tank, the filter is located within the tank at the end of the carburetor pickup line. If the carburetor is mounted separate from the tank, the filter is usually on the fuel line somewhere between the tank and the carburetor.
A throttle body is fuel injected, A carburetor is not, Fuel injection responds better then a carb. and you have less problems with it. There is no comparison .
because its stupid
Substitute is a perfect replacement whereas an alternative replacement might not be in adequate or perfect measures.
its between the fuel tank, and carb. its round and about an inch long
In a double replacement reaction a change of bonds between reactants occur.
http://www.ma.utexas.edu/users/parker/sampling/repl.htm