Not sure about the springs' locations, I'm guessing they're between the exhaust canister and a mid-pipe? Got pics and measurements of the loops between which the springs are-supposed to span? Then you could try to match some springs from another manufacturer if they're no-longer available from Dale Walker. Too-short would probably be better-than too-long, as you can come up with some-sort of an extension to make the found springs work, to save you from welding on loops to fit the longer springs you get. Plenty of dirtbikes use springs for their exhausts. Perhaps you can go to a shop where they do dirtbikes and have them dig-up something that works.