As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON RUN UP, FOUND THAT THE THROTTLE CONTROL WOULD STICK AT LOW RPM. WHEN ENOUGH FORCE WAS APPLIED TO MOVE PAST THE STICKING POINT THE RPM WOULD JUMP 200-400 RPM. AFTER DISCONNECTING THE THROTTLE CONTROL WE FOUND THE CONTROL WAS SMOOTH. THIS MADE IT DIFFICULT TO GET A CONSISTENT IDLE RPM AND MIXTURE SET.