As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ENGINE RAN RICH, UNABLE TO ADJUST IDLE MIXTURE. REMOVED SERVO FROM ENGINE AND INSPECTED IDLE MIXTURE PLATE FOR GALLING. PLATE WAS FOUND GALLED. SERVO SENT TO PRECISION FOR REPAIR. THIS SERVO HAS 36 HRS TT SINCE NEW. 7 HRS SINCE PRECISION REPAIRED SERVO AT FACTORY.