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MG MGA - Pertronix distributor

I tried to install a new pertronix (Flame Thrower) in early July. I lined up the timing mark and the rotor was at #1, but when I tried to install the new one I found that with the drive dog in proper position to go into the slot, the rotor was pointing 180 degrees away. Tried moving the wires to new positions, on assumption this was now #1 but it wouldn't run. I took it out and put the original back, thought about it for a while. Today I tried again. The drive/rotor relative positions on the two distributors are still 180 degrees different.
I know being 180 degrees off is a common error, but this doesn't seem to fit that scenario. I can't believe this one distributor is defective, so what am I missing?
Thanks! Jack Bissett, Lexington, VA
John Bissett

John
I had no problems installing the 123 distributor shouldnt you just turn the Petronix 180 degrees before installing or is this too simple
Paul
P D Camp

Sometimes the drive dog on the bottom end of the distributor shaft may be installed wrong. In that case, punch out the roll pin, rotate the drive dog 180 degrees, and reinstall the roll pin (don't lose the shim washer). Before you do it, be sure you know which way it should go so you don't end up with two wrong.
Barney Gaylord

Thanks Paul, but see Barney's comment. And thanks Barney. That possibility had occurred to me last night. I'll go very slow and see if that resolves it.

Many thanks,
jack
John Bissett

Hi John I fitted a Pertronix unit in my 1500 A 3 years ago, works very well. Recently also fitted a 40k volt coil and iredium plugs set at 34 thou gap. With timing at 34% max. I have a very sweet running engine through the rev. range. P.S. with a 3.9 B diff it sings along in the 60/70 MPH range .. Sean
S Sherry

Hi Sean,
Sounds like you have a mighty nice car. I did upgrade to a 40K coil, but haven't re-gapped the plugs yet. Here's a question: some oil gets through and fouls them pretty easily. Would a wider gap make it better or worse?

Thanks,
John
John Bissett

This thread was discussed between 12/08/2011 and 27/08/2011

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