g. During weekly maintenance checks external wiring is
cracks, cuts, fraying, and kinks. The equipment should be free
of bare spots,
rust, and corrosion. "All screws, brackets, and other external
hardware should be
secure and ,undamaged. Monthly maintenance includes all of the
actions above plus
a check for possible MWO's and technical publication changes.
h. The three circuits in the armature test set are very basic and good
troubleshooting techniques will isolate problems quickly. A defective meter,
burnt-out bulb, and defective switch or transformer are corrected by replacement.
Open and shorted circuits can be repaired or replaced easily. When properly
maintained the armature test set will give many years of trouble-free service.
IGNITION TIMING LIGHT MAINTENANCE.
a. The ignition timing light (fig 2) is a simple electrical device used by
maintenance men to set the ignition timing of engines. The light is activated by
the high voltage surge to a specific spark plug on the engine used as a timing
reference (usually the number 1 cylinder plug). The light flashes allow the
maintenance man to observe the timing of the engine while it is running and adjust
the distributor for peak engine performance.
b. Supervisors when checking this instrument should pay particular
attention to the condition of the leads and overall cleanliness of the instrument.
The operator is responsible for cleaning the instrument and is required to check
the condition of the leads before and after use. During use the operator checks
for overheating and erratic light operation.
c. The ignition timing light is an essential item which is normally trouble
free. A simple, basic, circuit design makes rapid troubleshooting and repair
possible. Malfunctioning components and open or shorted wires can be quickly
located by repairmen with good troubleshooting techniques. Continuity checks are
normally used when troubleshooting this equipment.
MAGNETO TIMING LIGHT MAINTENANCE.
a. Maintenance men use the magneto timing light (fig 3) to obtain breaker
point synchronization. Efficient firing of the combustible mixture in the engine
cylinders is accomplished by means of identically delivered magneto ignition
sparks. This equipment is used for synchronizing two sets of breaker points on a
single magneto, or for synchronizing two different magnetos to the same engine.
b. Operators should inspect the leads, case and headphone prior to
energizing the circuit. Then the toggle switch is placed to the ON position. Both
lamps should light and the audio tone of the vibrator should be heard on the
headphone. If the lamps and vibrator operate, the battery can be Judged "OK" and
the equipment is ready to use.
c. During operation the equipment user should check for correct lamp
operation and overheating. The operator's after-operation procedure requires a
cleaning and general inspection of the instrument.
d. Periodically the battery should be checked with a voltmeter (1,000 ohms
per volt or better). Replace the battery when the voltage drops below 4 volts with
the magneto timing light ON. Check lamp sockets, headphone jack, and vibrator
socket for dirt and corrosion during periodic servicing. The frequency of periodic
services should be determined by the individual unit. If, for example, battery
failure is occurring during normal daily operations, the frequency of periodic
checks should be increased.
0S 010, 8-P4