I have an old echo gt-2200 string trimmer that is not running right. It starts and idles fine but when squeeze the throttle, its hesitant to rev up and at wot its kind of boggy. I removed the spark arrester and cleaned the exhaust port, even tried running it with no muffler, still no change I put a new spark plug in, still nothing I took the carb apart and cleaned every hole with carb cleaner I tried choking while it was running to see if there was a lean condition but it didnt help. I hit the primer bulb while it was running, it bogged I took the fuel filter off and ran it without it for a minute, still nothing. There is only one adjustment screw on the carb. Its a walbro wy series. setting it to one click leaner, kinda clears it up a little but but still not right. Im thinking maybe i need to rebuild the carb with some new gaskets but who knows.