TM 5-4240-501-14P
IGNITION
General
Repair Instructions IV (Form 4750)
Section 2
IGNITION
Three basic types of ignition systems are used
1.
MAGNETRONTM ignition, a self-contained
transistor module (no moving parts) and ignition
armature.
2.
A flywheel type, having either an internal or
external breaker system. Fig. 4 and Fig. 25.
3.
The Magna-Matic system, having the armature
and rotor behind the flywheel, and an external
breaker system. Fig. 44.
Check Ignition
Remove the spark plug. Spin the flywheel rapidly with
one end of the ignition cable clipped to the 19051 tester
and with the other end of the tester grounded on the
cylinder head. If spark jumps the .166" (4.2 mm) tester
gap, you may assume the ignition system is functioning
satisfactorily.
Fig. 1.
NOTE:: Flywheel must rotate at 350 RPM, minimum with
MAGNETRON’" ignition.
Fig. 1 - Checking Spark
NOTE: If engine runs but misses during operation, a
quick check to determine if ignition is or is not at fault
can be made by inserting the 19051 tester between the
ignition cable and the spark plug. A spark miss will be
readily apparent.
While conducting this test on Magna-Matic equipped
engines. Models 9, 14, 19 and 23, set the tester gap at
.060" (1.5 mm).
SPARK PLUG
The plugs recommended for Briggs & Stratton engines
are as follows:
1-1/2"
2"
Manufacturer’s
Plug
Plug
Part Number
CJ-8
J-8
Champion
RCJ-8
RJ-8
Champion Resistor
235
295
Autolite
245
306
Autolite Resistor
WS9E
-
Robert Bosch
3/4"
13/16"
Plug wrench (deep socket)
NOVEMBER. 1983
Clean spark plug with a pen knife or wire brush and
solvent and set gap at .030" (0.75 mm) for all models. If
electrodes are burned away, or the porcelain is cracked,
replace with a new plug. DO NOT USE ABRASIVE
CLEANING MACHINES.
Fig. 2.
Fig. 2 - Adjusting Spark Plug Gap
Coil and Condenser Testing . All Models
Use an approved tester to test coils and condensers.
Specifications are supplied by the tester manufacturer or
refer to MS-7862, Testing Briggs & Stratton Ignition
Coils.
NOVEMBER, 1983
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