AG Mechanics CDE Practice Exam

The proper spark plug gap for most small engines is:

1. .03

2. .10

3. .15

4. .20

The correct answer is: .03

The proper spark plug gap for most small engines is usually around .03 inches. The gap is the distance between the center and the side electrode on the spark plug. Having the correct gap ensures the spark plug can properly ignite the air-fuel mixture in the engine for efficient combustion. An incorrect gap can lead to misfiring, poor engine performance, and even potential damage to the engine. Options B, C, and D (.10, .15, .20) have larger gap measurements, which are not typically suitable for most small engines. It's essential to follow the manufacturer's recommendations for the specific engine to ensure proper performance.