Texas FFA Nursery Landscape Practice Exam

What is a potential drawback of using 2-cycle fuel in a 4-cycle engine?

1. It can lead to reduced power output

2. It can cause excessive wear on engine components

3. It may produce harmful emissions

4. It can contaminate the oil system

The correct answer is: It can contaminate the oil system

Using 2-cycle fuel in a 4-cycle engine can lead to contamination of the oil system. This occurs because 2-cycle fuel typically contains oil mixed in to lubricate the engine since 2-cycle engines do not have a dedicated lubrication system. When 2-cycle fuel is used in a 4-cycle engine, the oil mixes with the fuel and can enter the engine's oil system. This can dilute the engine oil, resulting in reduced lubrication effectiveness, increased wear on components, and possibly leading to engine failure over time due to inadequate lubrication. In contrast, the other options highlight potential issues related to performance and wear, but the unique problem of contamination of the oil system is a direct consequence of using the wrong type of fuel, making it particularly critical to understand in the context of engine maintenance and performance.