Could this be a fuel tap problem

I've been having trouble to get my dt 125 To idle and rev properly but now I seem to have got it to idle better and adjusted the pv as the hole didn't line up and it seemed to pull and rev a lot better but after give it a quick ride to end of road and back to see if it was running ok which it was I started to ride home and about half a mile down the road it started bogging and losing power and when I kicked it over again it started and then just died could this be a problem with the fuel tap like dirt In the filter or something and if the rubber that joins the exhaust to the end can is knackerd and split could this cause and air leak or compression issues any help be much appreciated