yea,,its gettin a little dried out+crusty,,shoot it with some penetrating oil,all the return springs are "frozen",and need a little "help",,use wd40 or liquid wrench,or even drip some motor oil on it,and work the throttle back and forth by hand ,,,,,,but just wipe off the excess oil, so it wont attract excess dirt,,,ive had this happen to me,,ive never seen the shaft start to get "frozen" in the pump,or anything,,try it,,,,,