1. Remove the air filter.
2. Disconnect the cooling system steam outlet hose from the cylinder head cover.
3. Disconnect the crankcase ventilation hose from the cylinder head cover.
4. Remove the distributor cap and disconnect the wires from the spark plugs.
5. Remove the cylinder head cover together with the ignition wire bundle and the ignition distributor cover.
6. Remove the spark plugs.
7. Turning the crankshaft clockwise with a wrench on the pulley mounting bolt, set the camshaft to a position in which the cams corresponding to one of the cylinders are directed in the opposite direction from the rocker arms.
8. Check the clearance with a flat feeler gauge at both valves between the end of the ball adjusting screw and the valve stem. Make sure that the adjusting screw is in the correct position relative to the valve stem.
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Clearances in the valve drive mechanism, mm: the normal clearance between the end of the adjusting screw and the valve stem, measured with a feeler gauge, is 0.15 mm for the intake valves on a cold engine and 0.20 mm for the exhaust valves, and 0.30 and 0.35 mm, respectively, on a hot engine.
9. If there is any deviation from the norm, adjust the gap by turning the adjusting screw and loosening the lock nut.
10. After adjustment, tighten the lock nut and check the clearance, then adjust the clearance of the remaining valves in the order of cylinder operation (1-3-4-2).
11. After adjustment, install the cylinder head cover, having first checked the condition of the gasket. Screw in the spark plugs, connect the ignition wire bundle, install the ignition distributor cover and air filter, connect the hoses.