I had leakage issues with the B between the top plate and the bowl. The B has 4 screws holding the top plate to the bowl casting. YF has 7 screws holding the top plate to the bowl casting.
If memory serves me, mine is a model 2100. (Use the search tool- there have been many threads in the past concerning the models to look for. I believe carbking and atomarc, among others, had some good advice/observations.) Like the B, it is a manual choke. No difference between the two...except for the extra 3 screws and no leakage!
Just my experience.
Bill
