Once home (shop) upon first firing up the timing light, idle was around
P (TDC) and max advance at (approximately) 5k rpm was about 12 to 15
degrees short of M (maximum advance mark). I shut off and advanced
distributor. Static timing (eyeball wise since there is no mark) looked
about right. Car idled much better. Now max advance is 'only' about 10
degrees short of the M mark (eyeball wise).
Methinks there might be a problem with the centrifugal advance
mechanism. Didn't someone recently say in essence that the advance
mechanism on the MarelliPlex distributor sucked? I also gathered it did
so from birth.
My experience (4 of them) is that the MarelliPlex has less total advance
than the stock distributor, e.g., less range in the advance. I set
ignition with the maximum setting as far advanced as possible without
preignition, and forget about the idle setting. Works for both the weber
and spica setups.