What was found
PILOT REPORTED ENGINE RUNS ROUGH. CHECKED VALVE CLEARANCE AND FOUND NR 2 EXHAUST TO BE .083 INCH. REMOVED NR 2 EXHAUST PUSHROD. PUSHROD FOUND MUSHROOMED AND BALL END WAS LOOSE. SUBMITTER SUGGESTS INSPECTING PUSHRODS FOR LOOSE BALL ENDS ANYTIME THE 100-HOUR VALVE TAPPET CLEARANCE INSPECTION DISCLOSES A LARGER THAN ACCEPTABLE VALUE OR WHEN LOW POWER IS NOTED. REFERENCE LYCOMING SI 1388C AND SI 1068A.