2.1.8. Check of a compression

Before measurement of a compression check the level and a condition of engine oil. Besides, be convinced that the condition of a starter and the rechargeable battery meets standard.
Start the engine and warm up it up to the temperature of cooling liquid of 80-95 °C.
Kill the engine. Disconnect candle wires of high voltage.
Remove spark plugs.
Scroll a bent shaft of the engine a starter for removal of foreign particles from cylinders.

Fig. 2.8. Installation of a kompresometr

Establish компрессометр in an opening for a spark plug (fig. 2.8).
Press an accelerator pedal before full opening of a butterfly valve.
Scroll a bent shaft of the engine a starter and consider indications of a kompressometr.
Nominal rate: 1500 kPa.
Minimum admissible value: 1400 kPa.
Repeat measurement for all remained cylinders and be convinced that the compression difference between cylinders is less than extreme admissible value.
Extreme admissible value: no more than 100 kPa
If in any cylinder the compression does not correspond to the range of admissible values or the difference of compressions on cylinders exceeds maximum permissible value, fill in a little engine oil in an opening for a spark plug of this cylinder and repeat measurements.
If after oil filling the compression increased, then wear or damage of a piston ring and/or mirror of the cylinder are causes of defect.
If after oil filling the compression does not increase, then the burn-out or damage of a saddle of the valve, or leak of gas (pressure) through laying of a head of cylinders is the reasons.
Moment of an inhaling of spark plugs: 20–30 N · m.