I'm not new to riding at all, i'm just new to four strokes....i own a yfz450 and i wanna learn how to wheelie!!! I can pop-the clutch but my tires just spin....even if i'm on cement....when i'm on sand/dirt i still cant wheelie....my tires just keep on spining....my tires are basically new also!! i just cant seem to wheelie nice....oh and my yfz is MX setup....so i dont know if i'm missin out on sutn...??? thanks in advance guys....

Jonny