26-03-2021, 05:52 PM
Hi JonE
The electrical noise on all the wiring of an unsuppressed Seven when the engine is running is enormous. An old tech thermal flasher will be immune. A typical electronic flasher will go haywire. On the other hand, thermal flashers are a bit fussy about total bulb wattage, electronic flashers less so. Both types are supposed to flash rapidly if the load is much less than normal (= blown bulb warning).
Try 5000 to 10000 ohm suppression resistors (suppressor caps) at each spark plug, and/or try adding capacitors between the input and output of the flasher and ground. A value between about 0.1 and 0.5 microfarad with fairly short leads is best. The things that used to be sold as radio suppression capacitors are more convenient to connect to than wire ended ones intended for circuit boards, but either will work. Even an ignition condenser is worth a try.
The electrical noise on all the wiring of an unsuppressed Seven when the engine is running is enormous. An old tech thermal flasher will be immune. A typical electronic flasher will go haywire. On the other hand, thermal flashers are a bit fussy about total bulb wattage, electronic flashers less so. Both types are supposed to flash rapidly if the load is much less than normal (= blown bulb warning).
Try 5000 to 10000 ohm suppression resistors (suppressor caps) at each spark plug, and/or try adding capacitors between the input and output of the flasher and ground. A value between about 0.1 and 0.5 microfarad with fairly short leads is best. The things that used to be sold as radio suppression capacitors are more convenient to connect to than wire ended ones intended for circuit boards, but either will work. Even an ignition condenser is worth a try.