Another good reason to spray carbs, every now and then with carb cleaner and not W-D 40 or other sprays. Any oil product will attract dirt and gum up and bind the linkage. My 340 was starting to not have any balls (there is that word again) in power and it was the accelerator pump. (plugged openings and plunger seen better days). I cleaned the carb and installed a new plunger and was good to go.