Interesting. Quite often an engine will experience odd problems when it is updated (?) with a proprietary ign or carbs. Usually due to either improper installation of failure to simply read the instructions. However, on occasion, pre existing problems may be exacerbated by the added "improvement". The problem was probably always there, just not bad enough to notice?
I use the Petronix in the Lucas 25D and 45D dizzys of my two engines. I have experienced no problems with them....However, I only use the Petronix as a trigger for an MSD ign systrm. I have never used the Petronix as a "stand alone" system. Perhaps I'm not the best person to ask about such a setup.
One additional note, "backfiring due to burned ex valves"...I find it odd that owners of the vintage "twinks" (Lotus Twincam) are still having problems with "burned ex valves". The OEM parts were of particularly poor quality, "burning" frequently in even street applications. The OEM Lucas rev limiter caused all sorts of problems and possibly could have contributed to the overall poor reliability. Still, I solved that problem by 1970 or so...I used the ex valves from a Datsun L-18, properly modified, for the cure. Later even switched to L-20 intakes. Today, I use custom valves by, Manley and others. The old problems with the valve train simply no longer exist.
I have a race this weekend....When we get back I think I will install one of my spare Petronix in the Lucas 23D on my '59 Metropolitan as a "stand alone" system and see what happens.
Of course, this all assumes I can remember why I want to try it when we get back next week.....;o)
