Service difficulty report · Impulse Coupling

Difficulty date
January 17, 2017
Submitted
August 9, 2017
Operation
General aviation
Part
Impulse Coupling
Condition
Failed
Location
Magneto
Component
Magneto · Champion
Component part number
4371
Stage of operation
NR
How discovered
9
Nature of condition
O
Precautionary procedure
O

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

What was found

IMPULSE COUPLER ON MAGNETO WILL NOT RELEASE WHICH CAUSES A BINDING CONDITION. IF NOT DETECTED IMMEDIATELY CAN CAUSE DAMAGE TO THE LT IDLER GEAR THAT LINKS BETWEEN THE CRANKSHAFT GEAR AND CAMSHAFT GEAR. THIS CONDITION COULD POTENTIALLY CAUSE CATASTROPHIC FAILURE. THIS IS A CONDITION THAT HAS EXISTED FOR SEVERAL MONTHS. IT SEEMS TO BE LIMITED TO 4300 SERIES MAGNETOS WITH IMPULSE COUPLERS. THIS CONDITION IS SOMETIMES DETECTED DURING ENG PRE OIL, SOMETIMES NOT DETECTED FOR 2 TO 3 HOURS OF OPERATIONAL TIME. CHAMPION HAS BEEN CONTACTED AND IS AWARE OF THIS CONDITION. THERE DOES NOT SEEM TO BE ANY RESOLUTION TO THIS ISSUE FROM CHAMPION.