Have an 86' gasser that is in very good shape and runs like a top. I have noticed in the last few months that when I push down on the foot pedal it squeals a little-hesitates before it starts up. It doesn't happen all the time but most of the time and I kind a have to "pump" the pedal to get it start up. Had it tuned up last fall, was thinking the belt or clutch may need replacing? Any ideas before I take it to the shop?