Then the cause of

In the case when two neighboring cylinders have the equally low «compression», there is a high probability that the head laying of the head is broken between them. This can be checked by the presence of coolant in combustion chambers or in a crankcase. If the “compression” in one cylinder is no less than in the others, and the motor is idly operating, then the cause of the fist of the distribution valve distribution shaft can be the reason, or the burning of the valve saddle.