My echo PB755 has never felt like it had as much power as our older PB751 (i think). Now it is running poorly when in the "run" position and seems to run better at half choke than it does when in "run". I was thinking it may not be getting enough fuel but the fuel filter and lines all seem ok. There is no buildup in the exhaust screen either. Does this sound like a carb issue? Simple fix?