Slime is totally different than fix a flat. Fix a Flat will rust the rim, Slime doesn't. Changing a tire that has slime in it can be messy but I've had it done many times and the rim is still usable, just needs hosed off. You can buy Slime at any auto parts store or Wal-Mart but I think Wal Mart is the cheapest. Don't use foam filling cause that tire will be heavy as someone already mentioned but the ride will beat you to death, especially on a ztr.