The gas distribution mechanism requires periodic adjustment of the gaps between the rocker arms and valves, which should be performed on a cold engine after a mileage of 16,000 km
Or if signs of clearance violations appear (valve knocking, reduction in engine power, flashes in the carburetor, “shots” in the muffler) in the following order:
- – remove the vacuum regulator tube;
- – carefully remove the rocker cover, avoiding damage to its gasket;
– install the piston of the first cylinder according to mark 2 (Fig. 4) on the crankshaft pulley at TDC. during the compression stroke and use a feeler gauge to check the gap between the rocker arms and the valves of the first cylinder.
If the gap is incorrect, unscrew the lock nut 5 (Fig. 5) of the adjusting screw 4 and, turning the adjusting screw with a screwdriver, set the gap according to the feeler gauge, then, holding the adjusting screw with a screwdriver, tighten the lock nut and check again that the gaps are set correctly;
– after adjusting the clearances of the next cylinder, turn the crankshaft half a turn and adjust the clearances for the remaining cylinders according to their operating order: 1–2–4–3.
Gap between rocker arms and valves on a cold engine (at 15-20°):
For exhaust valves of the 1st and 4th cylinders, mm ─ 0.30-0.35
For other valves, mm ─ 0.35-0.40