Small Engines (Lawn Mowers, etc.): Sears Weedwacker...again, sears weedwacker, filter screen

Question
Sears model C944.517360  21cc/16" model

My Dad replaced the gas lines on this unit and it wouldn't stay running. Further investigation revealed the inside lines in the gas tank had rotted away too. I replaced the inside hoses too. It has 2 hoses in, one from the primer (bent tube)which I believe is the return line to the tank and just needs to be inside the tank. The other has about 4 inches of line inside and a filter on it. I removed the filter for now. I try priming the system but the gas will not pump through. I have taken the carb apart and cleaned anything I saw and it will not start at all now. Plug is clean and gas is good so I strongly suspect gasline/carb problems. What am I missing? Carb is the Zama model. Pumping primer does not bring gas through easily.

Thanks

Answer
I have not seen this problem on the Zama's but there is a check valve in the body of the housing.  Is the check valve sticking?

Did you use an air compressor to blow through all the carb orfices?

The main fuel line with the filter on it connects to the fuel pump side of the carb.  There will be a small filter screen just on the other side of the carb main fuel inlet to connect the main fuel line.

Is the primer bulb cracked?  Normally a crack will only be visible when you depress the primer bulb.

Let me know.
Eric