hi i just rebuilt my bike and overhauled everything took a few pics of exhaust cleaning process
pics 1 and 2 a heavy patina had been built up on the exhausts
pics 3 and 4 are after about 2-3 hours of sanding the downpipes with 800 grit first then thoroughly with 1000 grit paper
pics 5 and 6 are after i two stage polished them with polishing wheels attached to a heavy duty drill. i just use a nut and bolt for a wheel adapter and put it straight into the chuk.
i decided to polish my end can as well as it had some considerably deep scratches i managed to sand out
do not like this end can that came with the bike i think it might be a bit to big. might mod it or put a smaller one on
to clean the inside of the pipes i removed the end can. tipped washing powder into the pipes and my old steering bearings i had replaced. then filled with boiling water after plugging the ends of the pipes and just shook it around for twenty minutes .
turned out satisfactory thought i would share
have a good one