Carb troubles.....I think

[Jims85]

My 85 VF700C is lacking power after about 65mph.  Just had an overhaul done on all 4 and it's running lots better than before.  However, when trying to pass or even keep up with highway traffic most times, I can smoke everyone from 0-65 but after that, they blow my proverbial doors off.  I can feel it trying, almost like it's missing but I know it isn't.  It starts, idles and runs fine until then...I've had someone tell me it could possibly be the diaphragms maybe??  Any help would be greatly appreciated folks!