Originally Posted by crenwelge
I agree with Mike B that timing could be your problem. It almost sounds to me like your centrifugal advance is not working. Your centrifugal advance bumps up the timing while the vacuum retards it. If your centrifugal advance has broken springs, it will not advance and your vacuum will retard it. Check the vacuum advance for movement as you rev it up a little. Then disconnect it and rev it up a little and see if it advances. If not, remove the breaker plate and see what's wrong.
This sounds confusing to me. If the springs are broken it seems it would advance to easy. Ive been working on them for 60 years & have never seen this happen. Also i have never seen vacuum retard spark except like Jerry said somw Fords back in the early 70's had for emmissions.

They say money can't buy happiness. It can buy old Chevy trucks though. Same thing.
1972 Chevy c10 Cheyenne Super
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