Possibly, but unknown to me. I've run across a few that had undersized jets from the factory.
If these jets were improperly calibrated when assembled at factory, then there would have been a problem with engine to begin with.
Surging comes to mind.
Put your 90 jet in if you have a header/filter. With a free flowing pipe and air filter you need a jet with a .036 size. Most racers following AKRA rules are in the .035-.038 range to achieve optimal jetting.
On both of the clones that i did filter/exhaust mods to they started to break up on the top end and throughout the rpm band. They didn't do this stock. So why did the re-jet work then?
Then possibly it is out of spec.
Might be a good idea to check and adjust as necessary.
Just one thing to subtract from the possibility that this is the problem.
i dont beleive it is, i beleive its just a plastic float. with the needle on, could it be easier to help identify, if i had a video of what was happening?