100 Ignition ??

08 kx 100 , gets to about half throttle , then just dies out , let off , and it rums .... will not get over that rpm ... ran great last week . Carb is clean , idles perfect . On work stand , gets to a certain rpm and it misses , refires , misses , refires ... waaap waaap waaap waaap . Checked kill switch , no.. removed and cleaned coil mounting bosses , no .. ordered new coil , but am wondering ?? Cdi box ?? Any help ??
Maybe post some video?
Stuck power valve will have it losing power not miss. Is there an in-line fuel filter? Is the tank screen clean? Maybe the fuel valve is clogged or the line running to carb.
Remove the inline filter.