First, where did you buy your rebuild kit?
If it didn't come from carbking (Jon H) / The Carburetor Shop, there may be missing or incorrect parts. It's also possible that your YF is a cobbled together frankencarb sold by auto parts stores as a Fitzall when in reality it fits none.
Contact carbking with all the numbers on your carburetor and the numbers on the metering rod. He'll make sure you're starting off with the correct carb for your engine and see to it you have the right internal parts.
He's a member of this site and can be contacted via PM. carbking
Jon H
The Carburetor Shop
573-392-7378 (8:00-5:00 Mon-Tue)
