Analysis of the Causes of Insufficient Power in Single-Cylinder Diesel Engines

Diesel engines, as a crucial power source for agricultural machinery, play a vital role in agricultural production, widely used in tractors, rice transplanters, plant protection machines, harvesters, threshers, and more. After a certain period of operation, even with simple maintenance, these engines may still exhibit symptoms such as black smoke from the exhaust pipe, decreased speed, and lack of power, indicating insufficient diesel engine power.

Taking 8.8–19.8kW single-cylinder diesel engines as an example, the problems and solutions encountered in actual repairs are summarized below:

1. Cause Analysis

The most fundamental cause of insufficient diesel engine power is incomplete or inadequate combustion of diesel fuel in the cylinder.

The main reasons include: firstly, poor fuel supply, such as poor atomization; secondly, insufficient air supply; and thirdly, severe wear or incorrect installation of the fuel pump or related transmission components, especially installation problems, which are often overlooked. 2. Solutions

One of the prerequisites for a high-performance diesel engine is ensuring that diesel fuel and air enter the cylinder at a certain pressure, timed, quantitatively, and evenly for complete combustion. Therefore, insufficient power can be addressed using the following methods:

(1) Poor fuel injector atomization or stuck needle valve assembly. This is caused by severe wear and carbon buildup on the fuel injectors due to long-term operation under high temperature and pressure. To solve this problem, firstly, keep the diesel fuel clean during use; secondly, replace severely worn and carbonized fuel injectors; and thirdly, correctly adjust the injection pressure and ensure appropriate spray and range.

(2) Clogged air filter. Because diesel engines operate in harsh environments for extended periods, dust accumulates on the filter element, obstructing air intake into the cylinder, reducing airflow, and causing incomplete combustion. The air filter should be cleaned or replaced with the same model.

(3) Severely worn or incorrectly installed fuel injection pump. Wear on parts can be addressed by adjusting clearances and replacing worn parts. However, incorrect pump installation will directly lead to inaccurate fuel supply, causing an imbalance in the air-diesel mixture ratio. Therefore, special care should be taken during installation.