Too much centrifical advance?

[stevec5000]

I seem to be getting too much centrifical advance. At idle it's at F but instead of 36 degrees like the manual says mine goes all the way to about 43 degrees. I'm getting a little pinging on hard accelleration and I think that may be what's causing it.
What would cause that much advance, wear of some part of the mechanism?

[dragxs11]

Anyone can correct me if I'm wrong, but if your idle is turned up to high the butterfly valve in your #2 carb will open too much, causing more vac. on the advance. Ergo, if there is something wrong with your idle circuits, you may be compensating for it by turning up the idle screw. Or, your carbs could be out of sync. Thats the first thing to come to my mind. I think that about all that can go wrong with the vac. advance diaphram is that it can leak, and that would cause retardation ....retardation, thats funny.

[stevec5000]

Actually the vacuum advance is disconnected for checking this, you were close though. The vacuum advance mechanism is what holds the plate in position the pickups are mounted on with an arm that comes out and fits over a pin. The pin was loose in the plate allowing it to move around. I took it off and put a screw in it to replace the pin.

[dragxs11]

Ah! excellent! Yes, I suppose that would do it. And good thinking to remove the vac. adv. I had bypassed that thought.

[TopCatGr58]

Hey there Steve,

I was thinking about what you said, and thought that loose/worn springs might allow it to advance too far, or too soon?

I found this Tech Tip about the Centrifugal advance system by Blain Hoopes, might prove helpful!?
Centrifugal Advance
T.C.