The primer outlet valve on zama carb is leaking. How can I fix this?

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.

Sounds like you either have a hole in the fuel line or the primer bulb valve is leaking and drawing up air instead of drawing the fuel out the tank

This the basic plumbing diagram for remote primer. Both the carburetor and fuel may look different on your setup as your would gave either a Walbro WT324 pr a Zama C1Q-W8 carburetor.

The rubber check valve is part of what is called the primer base assembly. That is a part all unto itself and includes the check valve. Here is a carburetor break down with parts and diagrams.

http://www.lawnmowerpros.com/PDFs/Zama/C1U_PARTS_LIST.pdf

Homelite wants to sell you a new carburetor assembly. Your blower came equipped with a RuiXing brand carb. RuiXing does not offer any repair parts for their carbs, only replacement units.
Now for the good news....a Zama brand primer bulb fits perfectly on the RuiXing carbs. Check with your local small engine repair shop for a Zama primer bulb. The blower requires removal af the carb to get at both of the screws that hold on the bulb. It is not difficult, just one nut holds on the outer airbox cover...don't lose the little washers. Then one long stud and one short screw will take the carb off. Replace the primer bulb and reinstall everything the same way it came off.
Good luck!

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

Any local small engine service shop should have these parts in stock. Its called a 'primer bulb'.
Determine if the primer bulb is part of the carb or sperate from the carb with fuel lines connecting them. If seperate remember how the 2 lines get connected when you remove the bulb and replace with a new one. If a part of the carb...
You need to determine if the carb is a Zama or Walbro. It will have the name stamped on the carb. All Zama carbs use the same bulb. Walbro has a small and large bulb.
It would be worth while to install a new carb kit while you have the carb off and apart

Carefully unsrew the two screws in the plate holding the primer bulb down and just remove it while holding the rest of the carb down. Take the bulb to a parts/repair shop and buy another bulb for a Zama carb and reinstall.

Sounds like the carb or gasket around the carb is leaking allowing the pressure to blow by when you press the primer bulb. If its not air tight it will not pop back out. Check your carb and surrounding gaskets and check for a leak.

joe

Sometimes even if the diaphram and gaskets look ok they may not be. If the diaphram is stretched or distorted even a little they wont work properly,same for gaskets and other parts of the carb. sometimes the littlest things can make a big difference. I would try a complete rebuild kit and while everything is out of the carb. spray the carb real good and then lite-ly blow out the carb. with an air hose also if you take a twist tie from bread and take off half of the paper from the wire and carefully probe all holes in carb. that might do the trick for ya. After you put the high and low adjustment needles back in (if your zama carb. is set up with them) you'll want to set the low needle (after turning all the way in till it just bottoms) at 1 and 1/4 turns out and the high at just about 1and 1/2 turns out, then while running make final adjustments.