- disconnect the air hoses from the automatic starting device and unplug it;
- warm up the engine by running it at 2000 rpm until the thermostat opens. Do not warm up the engine at idle speed, as after several minutes of operation in this mode the carbon monoxide (CO) content in the exhaust gases will be distorted;
- make sure the air filter element is clean. Adjust the engine idle speed without removing the air filter;
- check the technical condition of the ignition system and the ignition timing;
- make sure there is no outside air leakage (through the vacuum hose connections, carburetor sealing gasket, etc.);
- make sure there are no significant leaks in the exhaust system;
- make sure all high load power consumers (electric cooling fan, headlights, rear window heating element) turned off.
Using the mixture quantity adjusting screw 1 (see photo), set the crankshaft speed within 800-900 rpm on vehicles with a manual transmission and within 950-1000 rpm on vehicles with an automatic transmission.
The best way to regulate CO content in exhaust gases is with a gas analyzer. If you don't have one, you can achieve the required CO content as follows:
- set the correct idle speed of the crankshaft;
- remove the plug from the adjusting screw 2 of the mixture quality (composition) and, turning it in the desired direction, set the maximum crankshaft speed;
- use screw 2 to restore the normal crankshaft speed and repeat the above operations until the engine increases its speed without interruption and does not stall when it decreases;
- reduce crankshaft speed by 50 rpm;
- replace screw cap 2.
To adjust the CO content in exhaust gases using a gas analyzer:
For details, see the website [Mazbook]
- set the desired speed of rotation of the crankshaft at idle;
- remove the screw plug 2 and, turning it in the desired direction, bring the CO content in the exhaust gases to 1.5-2.0%;
- repeat, if necessary, the adjustment of the crankshaft speed with screw 1;
- repeat these operations until you set the CO content within 1.5-2.0% at the required crankshaft speed.