i HAVE A 70CC QUAD FOR MY SON IT RAN GREAT SHUT IT OFF THEN TRIED TO START AND THE STARTER JUST MAKES A ZINGING SOUND TOOK THE SAID OFF WERE THE STATOR IS AND THE STARTOR IS SPINNING THE CHAIAN BUT NOT TURNING ENGINE HOW DO I GET THAT PULLEY OFF AND SEE WHY THE CHAIN JUST SPINS AND NOT THE PULLEY TO THE ENGINE