A bit of google searching suggests that this is the right bulb.
I can't find a better picture of it or the specs on it, to be sure.

KAK-53020-234B

http://www.cruisercustomizing.com/kawasaki-fire-and-steel-replacement-spotlight-bulb-vulcan-1500-classicfi-and-nomadfi/part/KAK-53020-234B

It might be worth a phone call to get some more details.

Allan