Small Engines (Lawn Mowers, etc.): shindaiwa t 20 trimmer, tank fuel, shindaiwa

Question
My Shindaiwa t 20 trimmer will run ok if I put gas directly into the carb but stops as soon as that small amount of  fuel is burned.  I have checked the line from the carb to the in tank fuel filter and it seems ok.  The filter itself, the one that hangs inside the gas tank is just a year old.  I've taken the carb apart, cleaned and tightened and put it back together--no change.  The primer bulb on the carb does not seem to function well.  I've also bypassed the fuel tank by running the fuel line into a separate supply of gas-still won't run beyond the few seconds it takes to burn the fuel I'm putting directly into the carb.  Again, the trimmer runs great for the few seconds it has fuel, but I can't seem to get the fuel from the tank into the carb.  Thanks in advance for your help  

Answer
Tom
i am sure this may be a 2 cycle trimmer. It  sounds like the carburetor is not sucking the fuel from the tank. You said you cleaned the carb, cleaning the carb sometimes doesn't do it you may have to replace the carb due to a faulty jet,port or clogged main jet which sometimes cant be cleaned out.

Thanks