Brown tarnish gunk on the carbs

[klimber]

Today while cleaning up the bike I notices that the right hand carb was nice, clean and looking good but...........the left hand carb was covered in brown hardened stuff, kinda look like some one painted stain on it, it cleaned off the cleaner with a bit of rubbing.   I am assuming it is oil?  any ideas out there, think something is loose, needs a bit of tightening.   I never noticed this before!

[Turkina]

are you sure nobody was using it as a bong?  :mrgreen:   Though you would probably know... *kaboom*

[KevinC]

It will be the residue left from fuel leaking and evaporating. It might be a fairly slow leak, but replacing hoses, and tightening screws would be a good idea.