Service difficulty report · Throttle Plate · Cessna 172N

Difficulty date
May 6, 2003
Submitted
June 11, 2003
Operation
General aviation
Aircraft
N738YH
Make and model
Cessna 172N
Aircraft serial
17270338
Engine
Lyc O320H2AD
Part
Throttle Plate
Condition
Worn
Location
Carburetor
Component
Carburetor
Component part number
105135
Stage of operation
NR
How discovered
O
Nature of condition
K
Precautionary procedure
K

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

CARBURETOR WAS LEAKING FROM ACCELERATOR PUMP SHAFT SEAL. IN ADDITION TO PUMP SHAFT SEAL, UNIT WAS INSPECTED AND WAS ALSO NOTED THAT THROTTLE SHAFT AND BUSHINGS WERE WORN BEYOND LIMITS. INSTALLED THIS CARBURETOR BACK IN OUR CUSTOMERS PLANE, TEST FLEW WITH NO PROBLEMS. JUST A COUPLE OF WEEKS LATER, CUSTOMER WAS MAKING APPROACH. HAD PULLED THROTTLE BACK TO IDLE A LITTLE EARLY AND DECIDED TO PUSH THROTTLE CABLE FROM THROTTLE ARM TO SEE IF PROBLEM COULD BE IN THE CABLE. IT WAS NOT, ARM ON CARBURETOR WOULD NOT MOVE. THROTTLE PLATE MAY HAVE COME LOOSE AND CAUSE A BINDING SITUATION. ONE SCREW ON PLATE WAS SLIGHTLY LOOSE, BUT EVEN WITH PLATE REMOVED THERE WAS BINDING. SENT CARBURETOR BACK FOR REWORK.

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