It can be assure that diesel belches out black smock is mainly because of the imperfection of fuel nitrogen conversion rate. While, there are still some tips to reduce or even eliminate the black smock.
1. Frequently clean the air filter. The tank of the diesel isn’t hermetically sealed and long-term exposure to air, which cause some suspended impurities and dust dropping in to the air filter, then the gas port that is used for providing oxygen has blocked, at last, affect the fuel transformation due to lacking of oxygen.
2. Choose good quality fuel. Inferior fuel can easily stop up the passage of the oil pipe and cause the insufficiency of oil supply, then the remaining fuel deteriorate and generate black smock.