1999 KX125 doesn't rev smoothly up top

ever since i bought this bike last season, with a just installed top end, it seemed to be cutting off or reving roughly up top(kind of like a puttering) but through the bottom and mid it runs perfectly fine.
i don't think the reeds where ever replaced and could that be the problem? what do you think?

if i got new reeds would the boyesen super stock reeds perform well or should i get the pro series reeds? AND if i got the pro series could i just move the clip in the needle to help lean it out or would i have to buy a few jets from a dealer?

yea that may be the problem b/c i do go through a plug each time at the tack so it may be a tad too lean. but instead of using a leaner main jet could i just change where the clip is?? b/c i don't know where to get a jet pack.