3.5. Adjustment of thermal gaps in the valvate mechanism of the carburetor engine


The measurement and adjustment of gaps is carried out on the cold engine.

We uncover heads of the block of cylinders (see Replacement of laying of a cover of a head of the block of cylinders).
We uncover the ignition sensor distributor (see Removal of a cover of the sensor distributor of ignition).
We turn a bent shaft for a nut of fastening of its pulley clockwise …

… before coincidence of a tag (drilling) on a camshaft asterisk with a ledge on the case of bearings.

At the same time the tag on a pulley of a bent shaft has to settle down opposite to a tag of VMT (long) on a camshaft drive cover.

In this provision of shaft corresponding to the end of a step of compression in the 4th cylinder we check and, if necessary, we regulate gaps at the final valve of the 4th cylinder (the 8th cam) and the inlet valve of the 3rd cylinder (the 6th cam).
Consistently turning a bent shaft of the engine on 180 ° clockwise, we check and we regulate gaps of other valves in the order specified in the table:

Angle of rotation of a bent shaft, hail.

No. of adjustable valves (cams)
8 and 6
4 and 7
1 and 3
5 and 2

The angle of rotation of a bent shaft can be controlled also on the distributor runner. At turn of a bent shaft on 180 ° the runner will turn on 90 °.

For check of a gap we insert between the lever of the valve and a cam of the camshaft the wide flat probe 0,15 mm thick – for the inlet valve or 0,20 mm – for final.

At a normal gap the probe has to enter with an easy zakusyvaniye.

For adjustment of a gap a key "on 17" we weaken an inhaling of a lock-nut of an adjusting bolt, and a key "on 13" we rotate an adjusting bolt, exposing the required gap.

We tighten a lock-nut, holding an adjusting bolt from a provorachivaniye. Again we check a gap and, if necessary, we repeat adjustment.
It is possible to adjust a gap in the valvate mechanism with use of adaptation with the indicator. For this purpose …

… we install adaptation level on the case of bearings of the camshaft …

… also we fix a level on hairpins of fastening of the case.

We establish a rack with the indicator on adaptation level opposite to the checked valve...

… opiry an indicator rack yoke ledge about a valve lever nape.

We fix an indicator rack on a level. Having rested an indicator leg against other ledge of a yoke of a rack, …

… we fix the indicator on a rack.

Raising the valve lever a bifurcate plate of adaptation, we determine by the indicator a gap in the valvate mechanism according to the instruction to adaptation.

If necessary, we regulate a gap.