i bought my mc21 a few days ago and it has stalled on me a couple times now. Some times when i'm at a light in neutral, the revs start getting higher(without the accel) and then it goes back down and stalls. Another time is when i'm in first gear and reving up down the street it seems to struggle from 6000 rpm... i changed the plugs and a mechanic told me for 2 strokes i need to pull it above 9000rpm so the plugs dont get covered with oil.. what seems to be the problem??

And also what gear do you guys stay in traffic? i am always half clutching and moving in first but i'm scared its gonna stall on me again so...??

any suggestions?