The clearance is adjusted in the following order. Remove the cylinder head cover and the front protective cover of the toothed belt. Unscrew the spark plugs and remove the oil from the oil baths in the cylinder head. Inspect the surface of the camshaft cams: they should not have any scoring, cavities, wear or deep scratches. Install the 67.7800.9503 device for pressing in the valve tappets on the cylinder head cover mounting studs. Mandrel 1 can be used instead of the device (figure 50).
Figure 50. Recessing (a) and fixing (b) the valve tappets to replace the adjusting washer
Turn the crankshaft until the timing marks on the pulley and the rear cover of the timing belt are aligned (see figure 6), and then turn it another 40-50° (2.5-3 teeth on the camshaft pulley). In this case, there will be a combustion phase in the 1st cylinder. The crankshaft should be turned only clockwise either by the generator drive pulley mounting bolt or by the camshaft pulley using the 67.7811.9509 tool. Do not turn the crankshaft by the camshaft pulley mounting bolt, as this can damage the bolt.
Check the clearances at the 1st and 3rd camshaft cams with a set of feeler gauges. If the clearance differs from the norm, then use device 67.7800.9503 or mandrel 1 (see figure 50) the valve tappet is pressed down and fixed in the lower position by installing the retainer 2 between the edge of the tappet and the camshaft (67.7800.9504).
With the device 67.7800.9506 (steel plate with flat magnet) or using pliers with narrow jaws, remove the adjusting washer 3 and measure its thickness with a micrometer. Then determine the thickness of the new washer using the formula H = B + (A - C), where H is the thickness of the new washer; A - measured gap; B — thickness of the removed washer; C — nominal clearance.
Example: Let's say: A = 0.26 mm; B = 3.75 mm; C = 0.2 mm (for intake valve). Then H = 3.75 + (0.26 - 0.2) = 3.81 mm. Within the clearance tolerance of ±0.05 mm, we take the thickness of the new washer to be 3.8 mm.
Install a new adjusting washer in the valve tappet, remove the 67.7800.9504 lock and check the clearance again. If it is adjusted correctly, a 0.2 or 0.35 mm thick feeler gauge should enter with a slight pinch. Consecutively turning the crankshaft by half a turn, which corresponds to turning the mark on the camshaft pulley by 90°, adjust the clearances of the remaining valves, observing the sequence specified in Table 4. After adjustment, pour oil into the oil baths of the cylinder head so that the contact points of the cams with the adjusting washers are in the oil. Install the cylinder head cover and the front toothed belt cover.
Note: The cam numbers should be counted in order from the camshaft pulley.