the N68A is not a keihin factory needle.. It could be a needle taper desigend by the manufacturer of the bike (yam, honda, kawi, suzuki) So that needle was designed for little 80 and 85cc dirt bikes. Could be possilbe the they are aftermarket needles.. I only use geniune keihin jets.
I used the JJH needles also back when I used the 28pwks.