| 摘要 |
PURPOSE:To aim at making an air-fuel ratio alterable in a continuous manner as well as to improve a running feeling ever so comfortable, by having a separate secondary air leading port, in addition to the main secondary air leading port, opened on the upper course from an oxygen concentration detector. CONSTITUTION:When the air-fuel ratio of a fuel-air mixture at the suction side is not within the range of a specified value, an electronic control circuit 16 gives a signal for correcting this disparity to an air-fuel control motor inside a carburetor 11 and adjusts the mixture ratio. Secondary air to be added to an exhaust system for exhaust purification is added to the upstream of a catalytic converter 13 via a pipe 19 by operating a secondary air feeder 18. Aside from this, when an engine 1 is in a cooling state or when a car mounting the engine 1 is in a state of acceleration or running at the top speed, the electronic control circuit 16 makes a secondary air control valve 22 open and mixes the secondary air inside an exhaust manifold 8. |
