You seem to have checked out the major things. You ask if maybe the pump is not pickup up the fuel for some reason. What you can do is disconnect the line as it goes into the pump, then if you have an air supply, put the end of the hose in the gas tank opening, with a rag around it to help seal it, then, VERY GENTLY, let air into the tank, you should see gas come out of the other end of the line, VERY FAST, make sure you have something to catch the overflow, it should shoot out of the other end of the line like a shot. If this does happen then you know you have a clean route, all the way from your tank to your fuel pump, it will also blow out any air bubbles you might have in the lines. With the line off the intake side of the fuel pump, turn the engine over with a finger over the intake side of the fuel pump, you should feel the suction, this will mean that you do not have a cam problem, witch is what is turning over the lever on the other side of your fuel pump. If that is working, then hook it all back up, and go to your carb, disconnect the line as it goes into the carb, and once again turn over the engine. If you do not get gas out of the line, then the problem most likely is sill in your pump. You said you blew the lines out to the tank, but did you check the fuel pick up, inside of the tank. It has a small screen filter over the pick up tube, and some times these will get clogged up. That is why the test of blowing the gas from the tank, with the air line. Now make sure you do not put a lot of air into the tank, as you can bust a seam, if you put too much into it. It does not take a lot of air to make the gas come out of the other end. If it does not, then pull the sending unit out and check the filter on that end. Drain as much gas as you can out of the tank, so it does not come out of the sending unit hole, when you remove it. Good luck.
PS, have a fire extinguisher close at hand. Remember, if you do get gas out of the line, at the carb, have a rag or somehing to catch the overflow, and do not start or turn over the engine with gas on it, it could catch fire.
Thursday, April 13th, 2006 AT 2:12 PM