I accidentally published this post without any explanation the first time. Sorry.
Contrary to what your average bike night hero will tell you about Harley being all 'merikan. Evo and evo sporty carb's are Keihin and made in Japan. More importantly, contrary to what your average computer jockey partsman at the Kawasaki stealership will tell you, some readily available and cheaper Harley carb parts will work in your Vulcan 1500 carb.
Here's a typical Kawasaki CVK parts diagram for 1500 Vulcan Classic. The numbers are reference numbers not full part numbers.
Here's the list of parts that are common and not common between the Harley CV and the Kawa CV. This is not complete, but it's the ones I know for sure.
COMMON PARTS: Readily available from your local independent Harley shop.
Slow(Pilot) Jets (92064/A)
Slide Diaphram(16126). Easy to tear up and the Harley part is like $50 and the Kawa is over $100.
Accelerator Pump Diaphram(16014). $10 for Harley one, $40 for a Kawa one.
Accelerator Pump U-ring(92093)
Air Screw, spring, o-ring and washer(16014).
Fuel inlet elbow(shown, but not numbered). If your plastic one breaks get the all brass one from Harley.
ALMOST COMMON PARTS:
Harley main jets will not directly replace Kawa main jets(92036/A~D). However if you replace the Kawa emulsion tube(13280) with a Harley emulsion tube, then you can run any Harley mainjet.
NOT COMMON PARTS:
Float Bowl O-ring(92055A)
Here's the not common comparison of float bowl O-rings.
Here's the common accelerator pump u-rings side-by-side.