Service difficulty report · Throttle Body · Diamon DA20C1

Difficulty date
November 4, 2013
Submitted
September 14, 2015
Operation
General aviation
Make and model
Diamon DA20C1
Aircraft time
5,901 hours
Engine
Cont IO240B
Propeller
Snsnch W69EK63
Part
Throttle Body
Part number
6538481A19
Condition
Worn
Location
Engine
Stage of operation
IN
How discovered
9
Nature of condition
O
Precautionary procedure
K

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

What was found

(CAN) CONTINENTAL MOTORS REQUIRES A FUEL SETUP TO BE CARRIED OUT ON THE ENGINE IAW SID97-3(F). DURING THE SETUP THE MECHANIC WAS HAVING ISSUES SETTING UP THE METERED FUEL PRESSURE. METERED PRESSURE IS NORMALLY SETUP AT MAX RPM. HE FOUND THAT WHEN PULLING BACK SLIGHTLY ON THE THROTTLE THE FUEL PRESSURE WOULD JUMP BY OVER .5 A POUND. AFTER INSPECTING THE THROTTLE BODY HE FOUND THAT THE BLOCK THAT HOLDS THE STOPS, MAX AND MIN RPM, WAS LOOSE ON THE SHAFT. THIS WOULD ALLOW THE THROTTLE BUTTERFLY VALVE TO GO OVER CENTER. THE BLOCK IS HELD ON TO THE SHAFT BY A ROLL PIN. THE BLOCK COULD BE ROTATED ABOUT .0625 ON THE SHAFT. IT IS NOT KNOWN WHAT CAUSED THE FAILURE WHETHER IT WAS FROM MOVING THE THROTTLE VIGOUROUSLY OR IF THE PIN WAS AT A POINT OF FAILURE. A REPAIRED THROTTLE BODY WAS INSTALLED, FUEL SETUPS COMPLETED WITH NO FURTHER ISSUES. THIS IS THE FIRST TIME THAT THE OPERATOR HAS SEEN A PROBLEM LIKE THIS.

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