Service difficulty report · Carburetor · Cessna 172P

Difficulty date
April 21, 2005
Submitted
April 21, 2005
Operation
General aviation
Make and model
Cessna 172P
Aircraft serial
17275405
Engine
Lyc O320D2J
Propeller
Mcauly 1C160DTM
Part
Carburetor
Part number
105217
Part serial
75078018
Condition
Failed
Location
Engine
Stage of operation
LD
How discovered
O
Nature of condition
R
Precautionary procedure
O

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

What was found

ENGINE RPM WOULD NOT REDUCE BELOW 1300 RPM. INSTR ATTEMPTED TO LAND AC, BUT COULD NOT REDUCE AIRSPEED DUE TO HIGH ENG RPM. THROTTLE WAS ADVANCED TO FULL PWR SETTING, BUT ENG FAILED TO ACCELERATE. AC HIT FENCE, WAS DAMAGED. POST-ACCIDENT GROUND RUN, FOUND ENG WOULD NOT IDLE BELOW 1300 RPM OR ACCELERATE PAST 1800 RPM. COMPRESSION TEST PERFORMED, NR 3 CYL WAS FOUND TO BE 44/80 PSI, LEAKING THROUGH PISTON RINGS. ASSUMED NOZZLE WAS INGESTED INTO THE NR3 CYLINDER. WHEN CARBURETOR WAS REMOVED, IT WAS FOUND THAT ACCELERATOR PUMP DISCHARGE NOZZLE (TUBE) WAS MISSING FROM CARB AIR INLET. TUBE IS PRESSED-FIT INTO THE INLET CASTING DURING ASSEMBLY. SECOND CARB WAS INSTALLED, ENG RAN AT PROPER IDLE AND FULL POWER RPM.

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