Table of contents: Idle speed adjustment ↓ Checking and adjusting the starting… ↓ Adjusting the throttle valve… ↓
Idle speed adjustment
Adjust the idle speed on a warm engine, with the valve drive mechanism clearances adjusted, with the ignition timing set correctly, and with the air damper fully open.
Connect the tachometer and gas analyzer according to the operating instructions.
Check and, if necessary, adjust the amount of mixture of the additional idle system using screw 1 (see photo) and the engine crankshaft speed at idle within 900-1000 rpm; the electric fan of the cooling system should not operate.
Using adjusting screw 2 (see photo) of the mixture quality (composition), set the CO content in the exhaust gases within the range of 1.0-1.5%.
Checking and adjusting the starting clearance of the air damper
The air damper is driven by small and large pneumatic drives. In the hose connecting them there is a valve that opens the large pneumatic drive with a delay of about 2 s.
Remove the starter cover.
Open the throttle valve halfway with the choke valve fully closed, then release the throttle valve.
Using a screwdriver, push the pneumatic actuator rod 1 until it stops (see photo). In this position, using a rod or drill, measure the starting clearance of the air damper, which should be within 4±0.2 mm.
If necessary, achieve the correct clearance using screw 2 (see photo) to adjust the stroke of the pneumatic drive diaphragm.
Adjusting the throttle valve starting clearance
Remove the carburetor.
Close the air damper completely. Open it halfway, then release the throttle valve.
Using a rod or drill, determine the value of the throttle valve opening, which should be within 0.85±0.05 mm
If necessary, turn the adjusting nut (shown by the arrow in the photo) set the normal throttle opening value.