I know you can't adjust it but I'm just curious so wondered if anyone can help me out. I've had a bus in with a Petronix 009 distributor. It's fitted with the magnet type electric ignition module to replace the points and when I checked the dwell it was 68 degrees. I've had 2 buses with retro fitted electronic ignition modules like what is in the Petronix unit in the distributor and both read 45 degrees. Is 68 degrees correct?? It's Petronix product number #D1866
Could well be...but it doesn't matter. Just means current flows through the coil longer than it needs to to build a spark's-worth of magnetic field. A waste of electricity, if anything...
It will change very slightly by changing the gap between the pick-up and the magnet, but not a lot. There was a write up somewhere years ago where someone concluded that the only reason for the recommended gap was to ensure the bits didn't physically hit each other.
Cheers Zed. I've looked over the 2 units. The retro ones fitted has a gap of about 0.20mm while the Petronix one has a massive gap. The parts are also not interchangeable. I did find somewhere on the www a page about them being adjustable but it only gave a measurement adjustment of 1 degree either way. I did suspect it's a faulty but I need to make sure before I go back to the company. I've already taken something back recently to them.
I seem to recall measuring the dwell on a Pertronix and it was about 60*. As long as it works it doesn't matter.
I measured 54 degrees on the Pertronix unit on our bus the other day. That was simply setup with an adequate gap that looked like nothing would hit anything.. as I had lost the little bit of plastic they provided with the unit.
