Examination
1. Checking and adjusting valve clearances must be carried out on a cold engine.
2. Remove the cylinder head cover.
3. Identify a cylinder with equally open intake and exhaust valves and check the valve clearance on the cylinder with equally closed intake and exhaust valves (see Table 5.1).
Table 5.1. Cylinder number on which the check/adjustment is carried out depending on the cylinder number with equally open intake and exhaust valves
4. Using the crankshaft pulley mounting bolt, rotate the engine crankshaft sequentially by 1/4 turn and take the following measurement:
Fig. 5.1. Measuring the valve drive clearance with a feeler gauge
5. Use a feeler gauge to measure the clearance in the valve drive (Fig. 5.1). When measuring the clearance, the feeler gauge should fit very tightly.
6. Nominal value (engine cold):
- inlet valve 0.15-0.25 mm;
- outlet valve 0.35–0.45 mm.
7. If the clearance value is not within the nominal value, adjust it by performing the following operations.
8. Re-measure any gaps that are not within specification and record them.
Fig. 5.2. Measuring the thickness of the pusher: 1 – adapter; 2 – thickness (X); 3 – micrometer
9. Using a micrometer, measure the thickness of the pusher X (Fig. 5.2).
10. Select a tappet of such thickness as to provide the nominal clearance.
Pushrod thickness for adjustment = measured pushrod thickness (X) + (measured value – standard value).
The thickness of the tappets is 7.550–8.150 mm, with a step of 0.025 mm.
Attention! Measure the thickness of the pusher with a micrometer.
Caution: Always install new tappets.
11. Remove the camshaft and install the selected tappet.
12. Install the camshaft.
13. Turn the crankshaft in its normal direction of rotation and re-measure the valve clearances.