What effect does indirect combustion have on two-stroke engines?

Indirect combustion in two-stroke engines typically involves a secondary process where the fuel and air mixture is not directly ignited in the combustion chamber, but rather undergoes some form of pre-combustion treatment. This can lead to various inefficiencies in the combustion process, as the fuel may not burn as completely or as rapidly as it would in a system designed for direct combustion.

As a result of these inefficiencies, the engine's performance can suffer, leading to reduced effectiveness in converting fuel into usable power. The incomplete combustion often results in unburned fuel, potentially increasing emissions and decreasing overall engine performance. Therefore, the assertion that indirect combustion reduces the effectiveness of a two-stroke engine aligns with the principles of combustion engineering, making it the accurate choice in this context.

In contrast, the other options do not accurately capture the nuances of how indirect combustion affects performance in two-stroke engines.