Multiple module failures within a short period of time, raises the possibility that you are getting battery voltage to the module, at least intermittently, which could mean a short in the wiring, possible key switch problem that is being caused by vibration and bouncing.
Look at the side of the module where the ground wire attaches, and see if the epoxy is cracked, and you even be able to pick up a burnt wire smell if you put your nose close to it.
Inside the Magnatron ignition module (yours is a diff model than my Intek which uses Magnatron) are two transistors . You seem to be applying 12V sometimes. The transistors run on 5 micro amps (5 one millionths of an amp?). If you have applied bat voltage the little transistors are ruined and no amount of continuity check or probing will bring them back. It is characteristic of a a failed transistor to sometimes work, but not continuously. I have never seen any Briggs discussion of the guts of the module, probably because it's Greek to many on the forums. These modules are probably encapsulated (potted- after the circuit is soldered up it is placed in a mold and a special casting resin is poured in, then cured.) The modules live bolted on to the iron of the engine which is normally a "heat sink," which draws heat away from the transistors who only tolerate up to 250F (probably less). Vibration is also the enemy. It appears the pros know well how many ignition modules are ruined with the best intentions gone wrong. These modules are rugged while also being fragile (to stray excess voltage). Well again I am on my soap box, and before you can pelt me with garbage I sign off. Your humble servant.:laughing:
Inside the Magnatron ignition module (yours is a diff model than my Intek which uses Magnatron) are two transistors . You seem to be applying 12V sometimes. The transistors run on 5 micro amps (5 one millionths of an amp?). If you have applied bat voltage the little transistors are ruined and no amount of continuity check or probing will bring them back. It is characteristic of a a failed transistor to sometimes work, but not continuously. I have never seen any Briggs discussion of the guts of the module, probably because it's Greek to many on the forums. These modules are probably encapsulated (potted- after the circuit is soldered up it is placed in a mold and a special casting resin is poured in, then cured.) The modules live bolted on to the iron of the engine which is normally a "heat sink," which draws heat away from the transistors who only tolerate up to 250F (probably less). Vibration is also the enemy. It appears the pros know well how many ignition modules are ruined with the best intentions gone wrong. These modules are rugged while also being fragile (to stray excess voltage). Well again I am on my soap box, and before you can pelt me with garbage I sign off. Your humble servant.:laughing:
hnstr, It is frustrating to live in the digital age because just below the surface of the buttons is a very complex world few care to understand. If this forum stimulates even a few to pursue further study of e.g., transistors , this will be very good. But they cannot be understood with street sense. Far from an expert I did study this stuff many years ago. Ideas like "resistance" are really quite different when you study transistors. An education is available online , but probably somewhat frustrating. So the ignition module for most will be understood in this forum as simply "good" or "bad." Probably the best bet is to try to buy top line replacement which "should" have reliable parts inside and then do not overheat or allow stray voltage near them. Have a good holiday. motoman