BENDIX K SERIES MAGNETOS

SERVICE INSTRUCTIONS Scintilla Division, Bendix Aviation Corporation, Revised March 1956

DESCRIPTION

The Bendix K series magnetos are high tension magnetos designed for use on small one and two engines. They combine dependability with light weight and simplicity.

The rotating magnet turns in close relation to a pair of laminated iron pole shoes, the outer ends of which carry the coil assembly. The pole shoes as well as the condenser are secured to a mounting flange which is a sturdy aluminum casting. Generally, the breaker incorporates a follower which is actuated directly by the engine crankshaft cam. However, on some single cylinder engines, the breaker is mounted remotely from the stator plate and magnet and a push rod is provided to actuate the breaker spring for separating the contact points.

LUBRICATION

On breaker assemblies incorporating a cam follower felt, apply one (1) drop of S.A.E. No. 60 oil to the cam follower felt when the magneto is installed and, after each 100 hours of operation, apply two (2) drops of S.A.E. No. 60 oil to the cam oiler felt. Blot off any excess oil with a clean cloth. Clean any excess grease from the cam. Inspect cam surface for rusting, pitting or scoring. All damaged should be replaced to reduce cam follower wear. Keep oil and grease away from the contact point surfaces.

MAINTENANCE

Ordinarily these magnetos will operate over extremely long periods of time without the need for adjustment or repair. However, if engine operating difficulties are experienced which appear to be caused by the , the magneto output should be checked to determine if this unit is functioning properly.

This check is accomplished by disengaging the high tension cable from the and holding it by its insulation in such a position that the metal terminal is about 3/16 inch from some grounded part of the engine. While holding the wire in this position, spin the engine over at normal cranking speed. Removal of the spark plug will make it easier to spin the engine over. If the magneto sparks this gap, the trouble is not in the magneto.

Should the magneto fail to spark, inspect the contact breaker. If the magneto incorporates a cover, it will first be necessary to make out the securing screws and remove the cover.

If the contact points are dirty, they may be cleaned with a little clear gasoline. Be careful to keep gasoline away from the cam follower felt if the contact points are cleaned while the breaker assembly is installed on the magneto. It is better to remove the breaker assembly, wash completely and then dry with compressed air. Relubricate cam follower felt before installing breaker assembly. Make sure no particles of lint are left between the point surfaces if a brush or cloth is used. If severely burned points are found in the pivot type breaker, both should be replaced by installing new support and lever assemblies. On the pivotless type breaker, it will also be necessary to replace the complete breaker assembly, as disassembly or replacement of individual parts of this type unit is not recommended.

See that the contacts are properly adjusted. K magnetos not having magnet incorporated in the should have contact points adjusted so when fully open, there will be eighteen thousandths (.018”) of an inch between the point surfaces. Check with a feeler gauge. If the contacts do not open the proper distance, loosen the screws which hold the contact breaker, and shift the assembly slightly to obtain the correct clearance of .018” between the point surfaces. K series flywheel type magnetos having contact point opening .018” stamped on stator plate should be set to a basic clearance of .015”. A tolerance of ± .003” is allowable. The .018” stamped on the stator plate is the maximum point opening and should not be exceeded. Check all terminals for good connections.

Most K magnetos have the breaker assembly mounted directly on the stator plate and actuated by a cam on the engine crank shaft. However, some one cylinder magnetos have the breaker assembly mounted apart from the stator plate and actuated by a cam and push rod arrangement. On equipment with engines using magnetos irrespective of whether the breaker assembly is mounted on the stator plate or apart from the stator plate, make sure the magnet has rotated a sufficient number of degrees past neutral at the time the contact points separate enabling the current to build up and produce a spark that will take place in the cylinder. The number of degrees past neutral is known as the “E” gap and may vary with different magnetos but in any case should not be less than 5 degrees.

After the above work has been completed, recheck the magneto at cranking speed as outlined in a preceding paragraph. This check may eliminate the necessity for removing the coil and condenser and is the most positive method of determining if the magneto is operating satisfactorily.

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