Hey George, the kind of drip you describe is completely normal and nothing to worry about. You will want to remove the muffler and clean it out well with a solvent or degreaser and, ideally blast it out with compressed air after but you should wait until you've broken in the engine a bit more until you do or you'll just have to do it again. That is unless it's getting so plugged up that it is resisting a proper exhaust flow and fouling your plug up. Keeping in mind that plugs will tend to foul a bit during break in with the heavier oil/gas ratio.