With the spark plugs removed and the ignition coil high voltage wire connected to «weight», turn the crankshaft until the oil pressure is registered by the sensor (if provided by design) or until the oil pressure warning light turns off.
Screw in the spark plugs, put on the wire ends and connect the high voltage wire of the ignition coil.
Make sure the carburetor throttle is closed; then start the engine. The engine should start after a short period of time, necessary for filling the carburetor with gasoline.
Immediately after starting the engine, set the idle speed to high to ensure increased oil pressure in the lubrication system and quickly warm the engine to operating temperature. As the engine warms up, watch closely for oil and coolant leaks.
Switch off the ignition and check the oil and coolant levels. Start the engine again and check the ignition timing and idle speed. Adjust them if necessary.
Drive on a light highway section, accelerate the vehicle from 50 km/h to 90 km/h by depressing the accelerator pedal fully open. Then release the accelerator pedal, braking the vehicle with the engine to a speed of 50 km/h.
Repeat the cycle 10-12 times. In this case, the piston rings are worn to the cylinder walls. Check the oil and coolant levels again.
For the first 1000 km, do not subject the engine to heavy loads (move at low speed), by periodically checking the oil level. During the break-in period, increased oil consumption is possible.
After a run of 1000–1200 km, change the oil and oil filter, tighten the cylinder head bolts and check the clearances between the valves and rocker arms.
For the next few hundred kilometers, drive the vehicle normally, avoiding too much or too little load.
After 4000 km of run, change the oil and oil filter again, after that the engine is considered to have been run in.