Texas FFA Nursery Landscape Practice Exam

What was likely wrong with Alan's mower if it vibrated excessively after sharpening the blade?

1. The spark plug was loose

2. The blade was made from inferior metal

3. The blade was out of balance

4. The blade had been overheated

The correct answer is: The blade was out of balance

Excessive vibration in a lawn mower after sharpening the blade typically indicates that the blade is out of balance. When a mower blade is sharpened, if one side is sharpened more than the other or if there are any irregularities in the sharpening process, it can lead to an imbalance. This uneven distribution of weight causes the blade to vibrate as it spins, which can also lead to further issues if not corrected. While the other options could potentially affect mower performance, they do not directly correlate with the issue of excessive vibration specifically caused by blade sharpening. A loose spark plug could cause engine performance problems, but it would not usually lead to excessive vibration related to the blade. Inferior metal in a blade may affect durability and cutting quality, but it wouldn't directly lead to vibration unless it was significantly warped or broken. Overheating of the blade could cause damage or warping, but it is not a common scenario immediately after sharpening when balanced properly. Thus, recognizing the signs of an out-of-balance blade is crucial for maintaining proper mower operation and preventing excessive wear on the mower's components.