Hi, i bought my first 4-stroke 2 weeks ago and i have 2 problems. 30 seconds after i start the bike the header exhaust gets red hot.I dont know many things about 4-strokes but it doesnt seem right to me. The other problem is that the bike doesnt idle well.Actually it idles but all of a sudden the revs go up.After a while they go down and up again. Does the bike need valve adjustment or is it something else? When i ride the bike it goes really well but these two problems worry me allot!