Briggs coil swap?

[rogerf]

Hallo folks,

For what it's worth, I believe that the Mega Fire module (21119-2161 IGNITER) available from Stens and others is designed for exactly the original situation described. That is to replace the points and condenser whilst keeping the original coil in use and undisturbed apart from a new connection. Seems like this module and others like it are based on the old Australian designed and manufactured (in Sydney) Atom ignitor (1976) which went out of production years ago when the patent ran out (2005). If you're interested how it works look up US patent # 5,058,543.

Models available seem to be Rotary Nova II module 8786, Stens 440-065 Megafire & 440-465 Megafire II, Oregon 33-053

These newer version modules are available on Amazon and eBay for about $17 or thereabouts. Some modules have the capability of reversible connections to take care of polarity issues and are marketed as universal. I understand that the same circuit is now used by many manufacturers and is often built into the coil assembly to keep the parts count down. This works now due to the very high reliability of well designed and well built electronics.

The original Atom ignition was made in several different types, colour coded as to the application. I believe that they were all the same basic module, but with changes to alter the ignition timing. It follows that there could be small timing changes when using a newer version. I have heard from old time mechanics around here who used the original Atom units that chainsaws could have the timing advanced by a small amount and that they used to run better and have more power after the points were replaced by the Atom unit.

Cheers, Roger