HELP! me please

could be leaning out in the top end. do a plug chop. new plug, warm it up good, get the spark plug worn in a bit, but high rpms. after its been ridden a bit, wide open highest gear then pull the clutch and kill it. pull the plug out and see what colour it is.
 
Dude if the piston was wrong way that means it was not broke in yet, u should not be hiten 4 gear yet ,until u break it in.