How should the spark plug gap be adjusted on a four-stroke engine?

The correct approach to adjusting the spark plug gap on a four-stroke engine is to ensure it aligns with the manufacturer specifications. The spark plug gap is critical for optimal engine performance since it affects the ignition timing and the efficiency of combustion. If the gap is not set correctly, the engine may experience starting issues, misfires, or reduced power.

Adjusting the gap according to manufacturer specifications is important because these specifications are designed to provide the best possible ignition performance for that specific engine model. If the gap is increased or decreased beyond these specifications, it could lead to poor engine performance and efficiency. Additionally, replacing the spark plug without adjustment might not resolve issues either, as a new spark plug could still perform poorly if the gap is not set correctly.

Thus, adhering to manufacturer specifications guarantees that the spark plug will function optimally within the operational parameters set for the engine.