Makes no matter chrome or nikasil one little defect it's under it, and eating away aluminum cylinder behind the coating. Tread lighty, I worked for Yamaha i know how easy it is to go from yep it's working, to well it's now scrap pile material bad part about chainsaw cylinders most places won't...
I would NOT use the M. acid to clean the cylinder, just use the scotch bright hone theory.... much less chance of damage to aluminum/seeping under a chrome defect.. if it's been scuffed/by a squeaked piston, the scotch bright drill will remove it without hurting the plating whatsoever...