Repair Instructions IV (Form 4750) Section 2 IGNITION

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 2 1