Not impossible, just not advisable. A lot of the generic parts work fine, some not so much, and (keystone I think) has been putting the wrong jets in some of their kits for years. Most of the kits have crap you don't need and not all the parts you DO need. unfortunately unless you have spare carbs it's a tear down, inspect, order parts, wait....... then reassemble process.
The ebay cruzin image BS34 kits seemed OK for gaskets etc. It came with an adjustable (groove and clip) jet needle and a needle jet that I haven't had the nerve to try. (yet)