I have a POULAN WEEDEATER model # FL20,and when I push the primer button down it won't spring back and,no fuel comes through the fuel line!? :(

I think you have a plugged gas line. The primer empties itself but can't refill and pop back out. I hate the next part. Try disconnecting and cleaning out the lines, dump the current fuel and refill. I usually break some small line during this process and end up with a pain in the kester repair.

Sounds Like You Have A Clogged Line, Or Inlet To The Primer Bulb. You Could Also Have A Stopped Up Filter.