[Bruce Edwards]

If it is popping out the pipes it is to rich. If you had it on a dyno they are only set up, in most cases, for temp at the time of the run. Not real settings for everyday driving. Start with small changes of 2 steps at a time. I bought a full set of jets some time ago with every size from 65-120 if I remember the spread correctly.
Remember the primary does 90% of all the fuel mixing you use short of running full out on the track that is.
The unleaded fuel does not burn the same way as the old leaded stuff did and a light dusting of black on the outside edge of the plug is pretty normal now a days.
With that said it should not POP out the side pipes. That is a sign of raw fuel in the pipes lighting up by the stray hot carbon thrown out during combustion. If it only does it when you let your foot off hard, as when you goose it, you may be seeing a powervalve set a bit low and dumping raw gas in as the intake pressure changes.