1978 kz650 B2 or B2A???

I did a search and couldnt really find an answer to this question, and wasnt sure where to post it, but here it goes.

I have a 1978 KZ650 which I previously thought was a B2 model, but am now not so sure... could be the B2A. I've been reading mixed things about the confusing model #s. engine VIN-KZ650BE082650, Frame - KZ650B-522346. Any help is appreciated. Whats the difference between the two? I've read the carbs are different but thats about all I can find... Are the color schemes different? Mine is black w/ a blue stripe and I think that its stock paint ??? Just got the bike.

Thanks

From a quick peruse of my old "Service spec handbook", Carbs were changed from 24's to 22mm Vm's, & lost @ 4 hp. H/l was changed to a sealed beam. sorry, thats all i've got. G

More info on the two models in this post:
forums.kz650.info/index.php?PHPSESSID=f7...63193dd&topic=3157.0

Your numbers are B2A. B2A is just a late production of the 78 B2. Paint ect was the same, carbs were changed for emissions compliance. Colors were either orange or blue, but they do list black as made but I really doubt it as I've still never seen an original paint 78 KZ650 in black where I've seen hundreds in blue or orange, so if it is black and original, there were very few in that color.

while we're talkin about it, my '78 kz650 is red. does that mean it's b2? it also seems mine came from canada according to the wiring diagram, i have no headlight on/off switch on the right side controls...or maybe it's cause it's a b2a?