Quote: So as the mechanical advance kicks in, it moves the rotor and reluctor wrt to the pickup, so the rotors alignment wrt the cap contact changes cause the cap contact didnt move. it has to
NO!!!!!
You are not thinking correctly. As the mechanical advance rotates BOTH the reluctor AND the rotor change TOGETHER. Their mutual relationship DOES NOT CHANGE.
There are two relationships here.
ONE THe relationship between the points/ reluctor and the CAP
TWO The fixed relationship between the rotor and reluctor.
If the reluctor is off in relation to the rotor, you have a phasing problem.
BUT ONCE YOU FIX/ verify that, then the postion of the mechanical advance means not. THEY ROTATE TOGETHER
The vacuum plate DOES move the pickup/ points, which changes position IN RELATION TO THE CAP
You can NEVER have absolute dead center phasing with a vacuum advance, because THIS MUST HAPPEN. so now you have two choices:
ONE Optimise the vacuum advance position and live with what should be minor phasing change, or
TWO Align the phasing perfectly and weld the advance plate and do without vacuum advance.
I've seen hundreds and HUNDREDS of caps and rotors in my lifetime, and I'm getting to be on in years. In my opinion, this is an overblown "problem"
