When it breaks don't change it. Leave it as it is, with the split or crack, and assemble the tank as if it was new, basically a rubber bushing type block that the tank can rest on. The seat holds it down to a degree unless your bike is cartwheeling end over end down the road, but and at that point it doesn't matter about if the tank is held by that rubber, it's going to break or burn anyways. At least that's how I deal with that same problem on the 400 four ss.