What are the causes of low engine cylinder pressure?

[ODamian]

Engine cylinder pressure may be low due to the following reasons: 1. Air leakage between the cylinder head and the cylinder; 2. Air leakage between the spark plug gasket and the cylinder head or a faulty pressure relief valve; 3. Crankcase air leakage; 4. Severe wear between the piston rings and the cylinder or stuck piston rings causing air leakage. The diagnostic methods for low engine cylinder pressure include: 1. Unstable engine operation, with popping sounds from the exhaust pipe or backfiring in the carburetor; 2. Difficulty starting the engine when cold, with no significant change when climbing hills; 3. Water droplets being expelled from the exhaust pipe, backfiring in the carburetor, or water leaking into or out of the crankcase. A cylinder refers to a cylindrical metal component that guides the piston in linear reciprocating motion within the cylinder. Cylinders are categorized into: single-acting cylinders, double-acting cylinders, diaphragm cylinders, and impact cylinders.