I have a 07 piaggio nrg power dt air cooled still restricted and it has 8500 miles on the clock. It runs and I used it nearly every day going to and from school but it has some minor problems that I would like to correct. One being that when I turn it on it misses until the engine has warmed up and sometimes it dies. I can get it going again just with a clean spark plug but I don't know why the spark plug is getting dirty. Could it be that the mixture screw needs adjusting? Also when riding it accelerates to around 15mph and then the revs drop until around 22mph when it speeds up again. I think it may be a roller problem? Any advice appreciated. Thanks Bob
