The scheme of the device for supplying exhaust gases to the throttle valve of the carburetor
In the lower half of the body of the carburettor 1, where the throttle valve 2 is located, there is a technological plug 5 above the screw 6 for adjusting the idle speed (emulsion screw), which must be drilled. After it opens hole 4, ending with channel 3 of the idling system. In the hole you need to cut the thread M8x1, and drill the channel to a diameter. 6. The channel must be drilled accurately along the axis of the threaded hole. For this, it is necessary to make a conductor bushing with M8x1 external thread and a diameter hole. 6 mm, screw the conductor into hole 4 and drill through it. On the diameter of channel 3, two shallow horizontal grooves must be cut from opposite sides. This is necessary so that when the throttle pedal is suddenly depressed, there is no failure in the engine speed.
At this alteration of the carburetor, which at the minimum locksmith skills is available to the motorist, ends. A minimal alteration of the intake manifold 7 is also necessary. In its flange 8, in the area of the branch pipes through which the exhaust gases from the 2nd and 3rd cylinders are removed, it is necessary to drill a through hole and cut the M8x1 thread. Additional details are also required: a copper tube 9 and two nozzles 10 and 11. A coupling 10. it is necessary to screw into the body of the carburetor, and the fitting 11 - into the flange of the exhaust manifold. The copper tube should be 8x6 mm in diameter with two union nuts. The design of the ends of the tube together with the union nuts should ensure the tightness of the connection between the tube and the fittings.
After connecting the tube to the connections on the carburetor and the exhaust manifold, you can start the engine. Part of the exhaust gases from the 2nd and 3rd cylinders will go under the throttle and start fulfilling their noble task: not only save fuel by 25%, but also reduce the toxicity of the exhaust by half.
Literature: "IR" magazine No. 11/91