I have a BX, not a B, but my guess is that the bulbs are the same.
One of my hazzard bulbs went out about a year ago. It was very frustrating to discover that the bulb was either a proprietary design or some sort of odd-ball that you can't find in an auto parts store.
Even though we're only talking about a couple dollars, I was so pissed that I was being forced to visit the dealer for a simple bulb change that I bought an 1156 and filed off one of the nubs on the base to make it fit in the socket.
Yes, I checked very carefully first. The vertical orientation of a nub is the ONLY difference between an 1156 and whatever comes standard from Kubota.
Sheesh...
