At the risk of wasting time on a point that may not solve the oiginal issue and, also, at the risk of being flogged for missing the point, I am inclined to disagree with Andy about the bob weights. Constant RPM centrifugal force will keep the weights at a given, let's say "radius", which is held against the force of the springs trying to return them to the at-rest, minimum-advance position. On acceleration or deceleration, they go on the move until a new constant RPM is held. As I understand it, maximum advance occurs well before redline, but this should describe the behavior up until said maximum advance.
Richard L.