I just bought a used H 6522Ch. It would not start so I took off the carb, cleaned it and re attached it. The mower will not start without starting fluid. Sometimes it keeps running, sometimes it stops. The throttle seems to have no effect, even though the levers move. The one lever that does not seem to move is the little spring loaded one that attaches to the linkage then goes by a rod back into the motor. If I get the unit started and I push this, the motor revs. How can I get the unit started and get the throttle to respond to imput. Thanks! Norm