The phenomenon of insufficient cylinder pressure.

1. Excessive carbon accumulation and severe engine shaking.
2. Affects the combustion efficiency, power decreases, fuel consumption is too high, and even high temperature.
3. If it is caused by piston seal, it will also cause serious carbon accumulation in the combustion chamber and poor emission. And engine life is seriously shortened.
4. Combustible mixture downward scurry will increase the crankcase pressure, which will seriously cause the crankcase explosion; lubricant escapes into the cylinder, causing oil combustion.
5. Exhaust pipe smoke serious, the engine can not work properly or even stalled.

If it is a four-stroke engine, the main reason for the cylinder pressure is insufficient valve leakage, piston and piston ring and cylinder block gap is too large, cylinder gasket leakage, or replace the piston and other non-standard parts caused by the compression ratio and pressure drop.

1. Valve problems. For example, the valve sealing surface is bent, resulting in valve leakage. Or the camshaft is worn and the valve clearance is large, resulting in the valve not opening in place.
2. Piston rings are bad and become less flexible, and the piston leaks oil.
3. If the engine overheats and the cylinder block cracks, it is likely because the cylinder gasket is worn out causing the connecting rod to bend.
4. The engine cooling system is overheated due to water leakage and water shortage, and cannot be replenished in time.