Hi, I have a B&S Model 407677, Type 0182 E1, Code 030106YG, 21hp, OHV I/C, V-Twin engine that is smoking heavily out of the blower housing as well as the muffler. I just finished fixing one of the push rods as the rocker arm bolt came off on the left side and the engine would not start at all and when it did on one occasion it sounded like a machine gun firing. I am thinking that it is getting oil in the gas through the valve seals, but that's just a guess. Thank you, Jerry gwvaughn@toast.net