Discoloration of 439 SS with heat is to be expected. Inconsistency is also common. I cannot tell you why, only that I have observed it on numerous identical exhaust SS parts run in side by side test beds with exactly the same protocol. Only difference being weather and the particular test bed.
Easiest thing for cleaning the material (if you care *L*) is Bar Keepers Friend. it is primarily oxalic acid and if used as directed, will not scratch the pipes. One of the things I like about Adventure Tourer's is ZERO chrome to polish. I have left my pipes "au natural"
Easiest thing for cleaning the material (if you care *L*) is Bar Keepers Friend. it is primarily oxalic acid and if used as directed, will not scratch the pipes. One of the things I like about Adventure Tourer's is ZERO chrome to polish. I have left my pipes "au natural"