The top dead point (VMT) is the highest point through which passes the piston at operation of the engine. Each piston reaches VMT in compression and release steps, but the term VMT usually belongs to the piston of the first cylinder in a compression step. The label on a pulley of a quencher of the fluctuations fixed on cranked shaft, also belongs to installation of the piston of the first cylinder in VMT in a compression step.

Installation of the piston of the first cylinder in VMT in a compression step – an essential part of process on replacement of pulleys and a chain of a drive of the gas-distributing mechanism, and also on adjustment of a gap of valves.

Installation of the piston of the first cylinder in VMT make in the following order:

– before installation of the piston of the first cylinder in VMT switch off ignition and establish the gear shifting lever in neutral situation;

– put out of action ignition system, having disconnected electric sockets from ignition coils;

– for piston installation in VMT turn a cranked shaft clockwise if to take a detached view of the engine of a chain of a drive of the gas-distributing mechanism. Turn a cranked shaft a key for the central bolt of fastening of a pulley to a cranked shaft;

– turn out spark plugs and establish a tip компрессометра in an opening for a spark plug of the first cylinder. The tip компрессометра should be rolled in an opening for a candle and have length not less than 150 mm;

– turn a cranked shaft clockwise and at approach of the piston of the first cylinder to VMT компрессометр will start to show increase in pressure in the cylinder;

Fig. 3.52. Label combination on a quencher of fluctuations with a sign VMT or 0 on a forward cover of a chain

– continue to turn a cranked shaft before label combination on a quencher of fluctuations with a sign VMT or 0 on a forward cover of a chain (fig. 3.52) .

If компрессометр it is inaccessible, it is possible to close an opening for a candle a finger and by pressure increase at a provorachivaniye of a cranked shaft to determine, when compression in the first cylinder begins. Further continue to turn a cranked shaft before label combination on a quencher of fluctuations with a sign VMT or 0 on a forward cover of a chain (see fig. 3.52 ).

After installation of the piston of the first cylinder in VMT in a compression step, turning a cranked shaft on 180 °, it is possible to establish other pistons in VMT in sequence corresponding to an operating procedure of cylinders.