[SmallHurst]

Also, check to see if the vacuum advance is working properly. It could be that you have a leak in the canister and it does not show itself until the advance is needed. Pull a vacuum on the canister and see if it advances the weights like it should. Personally, when I am at the track, the advance is unhooked so that it has no possibility of coming into play. (Not like it would have a chance under a full throttle blast!)