Additional returns of point contacts that exhibit accelerated wear in magnetos with low service hours, prompting the issue of this Service Bulletin. Typical symptoms are unusual RPM drop during magneto check, difficulty starting, rough running engine, and/or unstable point timing upon installation.

Potential decreased service life of Slick 4-cylinder magneto distributor gear assemblies. Based on process and component improvements following the initial release of this service bulletin, the serial number range is being extended since the initial release. This condition was observed in magnetos with a varying number of service hours. Typical symptoms are unusual RPM drop during magneto check, difficulty starting, and/or rough running engines.

There have been limited reports in which impulse coupling stop pins have moved relative to the factory placement within the magneto frame of Slick magnetos. There has been one report of a liberated stop pin. A liberated stop pin could potentially enter the gear train of the engine, resulting in damage to the gear train, damage to engine accessories and could ultimately cause catastrophic engine failure.

There have been limited reports in which impulse coupling rivets have loosened relative to the factory placement. A loose or broken rivet could potentially enter the gear train of the engine resulting in damage to the gear train or damage to engine accessories and could potentially cause catastrophic engine failure.
This service bulletin has been updated to add the "TIO" engines to category 2 and make both alternative methods of compliance applicable to either category 1 or 2.