What direction does the fuel flow into a weedeater primer bulb?

The thing to understand is that this is not a primer, it is a purge and there is a big difference, a primer pushes fuel into the carb, a purge pulls fuel from the carb and dumps back to the tank, so when the bulb is pressed in, fuel in the bulb is pushed back to the tank, when the bulb comes our fuel is sucked from the carb, if the bulb stays in either the filter in the tank is blocked, or the fuel hose is trapped, or the filter in the carb is blocked, or somebody has fitted the pipes on the carb round the wrong way.

In regards to which pipe goes where, it's simple. If you pump your primer bulb with the pipes off, one side will suck and the other side will blow. The suction side will link to the outlet on the carb. The blow side will link to the return to tank. The fuel line with the filter on it will link to the inlet pipe on the carb.

The hose with the fuel filter will go to the bottom of the carb, the top hose off the carb will go to the inlet of the primer and the primer outlet will return to the tank

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I have no diagram but here are the instructions on how it goes.
The small diameter line out of fuel tank (has filter in-tank on end) connects directly to the side of the carburetor that has the fuel pump....that is the cover without the hole in it. Other larger diameter fuel line out of tank connects to the longer nipple on the external purge/primer bulb. The bulb "pulls" fresh fuel from the fuel tank to the carb and then out of the carb to itself, where it then "pushes" any air/old fuel back into the fuel tank. The remaining larger diameter fuel line in this setup goes from the metering chamber (has cover with writing on it and a vent-hole) side of the carburetor to the smaller nipple on the purge/primer bulb. Again, on the primer bulb, the longer nipple has a line going directly from it to the tank. This is the return line. The shorter nipple on the bub has a line from it going to the metering chamber side of the carb. If the purge/primer bulb is on top of the carb...small line from carb body to small hole in tank with filter. Larger diameter line goes from the bulb on the fuel pump side of the carb to the larger hole in the fuel tank where sometimes the line is held in place with a nylon nipple connector that keeps the line from pulling out of the tank. Otherwise, the line should enter the tank for about 1/2" or so.

The small diameter line out of fuel tank (has filter in-tank on end) connects directly to the side of the carburetor that has the fuel pump....that is the cover without the hole in it. Other larger diameter fuel line out of tank connects to the longer nipple on the external purge/primer bulb. The bulb "pulls" fresh fuel from the fuel tank to the carb and then out of the carb to itself, where it then "pushes" any air/old fuel back into the fuel tank. The remaining larger diameter fuel line in this setup goes from the metering chamber (has cover with writing on it and a vent-hole) side of the carburetor to the smaller nipple on the purge/primer bulb. Again, on the primer bulb, the longer nipple has a line going directly from it to the tank. This is the return line. The shorter nipple on the bub has a line from it going to the metering chamber side of the carb. If the purge/primer bulb is on top of the carb...small line from carb body to small hole in tank with filter. Larger diameter line goes from the bulb on the fuel pump side of the carb to the larger hole in the fuel tank where sometimes the line is held in place with a nylon nipple connector that keeps the line from pulling out of the tank. Otherwise, the line should enter the tank for about 1/2" or so.

There may be a malfunction in the check valves in the primer base assembly. Before attempting to get a new assembly, take the retaining screws at the bulb off, remove the bulb and spray the assembly liberally with WD-40 or an equivalent light lubricant. Sometimes this will free the check valves as they only let fuel flow one way and there are 2 of them in the primer base.
Do not use strong solvents, do not ever soak, and never use high PSI compressed air on these carbs. Sometimes, when the check valves in the primer base go bad, the carb floods and the reason is unclear. Zama doesn't list this as a reason for their carbs flooding, but they can. You may wish to view a parts breakdown list for your specific carb. You will need to know the type (stamped in side of carb body) and the model (stenciled in side of carb body). It will be something like a C1U type and a W-18A mode...thus its a C1U-W18A Zama carb. Here is a link to get you started.
http://www.zamacarb.com/pdfs/APPL_CR2010.pdf
Yours will be listed under Poulan/Weedeater

Presuming the primer bulb is on top of the carb....Fuel filter line out of gas tank goes to the lower part if carburetor body. The other line (normally larger in size) coming out of the fuel tank goes to the primer bulb outlet on the top of carb.
If the primer/purge bulb is not on the carb, things are a little different. The fuel filter line out of the tank still goes directly to the carb, as the bulb will pull old fuel/air out of the carb allowing fresh fuel to flow in and pushes old fuel/air back to the fuel tank.
Fresh fuel in, old fuel out of the carb...you can hook up a piece of fuel line to the bulb and tell which one is pulling and which one is pushing..or depress it with your fingers on it...either way you can tell.

The line with the filter goes to the bottom of the carb. The other line goes to the outlet side of the primer bulb and the other line from the primer bulb goes to the top of the carb (The primer sucks gas through the carb).
Good luck!
Ps. if you are not sure which nipple of the primer is the outlet port then put your finger on one of the ports and push the bulb. If the bulb stays ridged then that's the outlet and if it collapses but doesn't fill but up then that's the inlet side.

primer bulb on weedeater will not return to normal or **** gas into it. new primer bulb. lines to tank have been repalce and can blow through them but primer bulb will not push air into tank

Sounds Correct on this End.