TM 9-4910-644-14 & P
1-1. GENERAL.
This manual is the basic publication covering the
operation. maintenance and parts breakdown for the L i g h t ,
Ignition Timing, 4910-00-255-1449, PN 7710.
1-2. DESCRIPTION.
The timing light is a battery operated portable device which is completely self contained in a steel case and
cover assembly. All of the operating components are mounted on the removable front panel. The unit is nor-
mally shipped without batteries. Overall dimensions are 8 by 4-1 2 by 2-1 2 inches deep.
1-3. PREPARATION FOR USE.
Prior to initial use, fresh batteries must be installed. For battery installation see paragraph 1-10.
1-4. PURPOSE OF EQUIPMENT.
The timing light is used to indicate the point of opening of the breaker points in a magneto or other ignition sys-
tem. The timing light is a dual device and may be used to time a single magneto system or to time and synch-
ronize the points of a dual magneto system. The instant of opening of the points is indicated by the extinguishing
of neon glow lamps.
1-5. OPERATING INSTRUCTIONS.
Place switch to the ON position, both neon lamps will glow. Momentarily short each red (positive) lead, in
turn, to the black (negative) lead. This will extinguish its respective neon lamp and indicate proper operation.
1-6. TO TIME A MAGNETO.
a. Connect the black lead to the magneto housing ground. Connect either red lead to the breaker points pri-
mary terminal. Switch ON.
b. One neon lamp will glow when the points are open and will be extinguished when the points close. As the
engine is rotated in the proper direction, the lamp will remain off during the dwell period and come on at the
instant the breaker points open.
1-7. TO SYNCHRONIZE TWO (2) MAGNETOS OR A SECOND SET OF BREAKERS IN A DUAL MAGNETO.
a. Following the same procedure as paragraph 1-6, connect the other red lead to the primary of the other
magneto or second set of points.
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