I have a ECHO srm 2400 weed wacker with a zama c1u k18 carb in it. I know its not a chain saw but with the number of knowledgeable people here I'm hoping to get some help. I cleaned it by soaking it in Berrymans parts cleaner (paint can). It is spotless with new gaskets and diaphragms but it still wont run. I can't get it to prime!! When I pump the purge bulb it pushes bubbles into the gas tank. I think it has a bad check valve. Is there a valve in the primer base part or is the only check valve next tot the needle? Does anyone have experience on replacing check valves? How do you get them out?