Originally Posted by dyna mo

mazut!

Its all about the fuel.

Engineering difficulties are given as a potential reason for the Kuznetsov's super-smoky nature. Vice Admiral Pyotr Svyatashov explained, saying that because of improper calibration in the preheating or injection mechanisms, the Mazut injected into the combustion chamber might not have had time to combust fully—in other words, the partially burned products are causing the black smoke.