Is your lawn mower struggling to start, misfiring, or running rough? A faulty lawn mower spark plug could be the culprit. Our in-depth guide walks you through every step of lawn mower spark plug replacement, from identifying common symptoms like difficult starting and increased fuel consumption, to selecting the correct lawn mower parts for your specific engine. Learn when to replace a lawn mower spark plug, gather the right tools, and follow our clear, step-by-step instructions for safe removal and installation. This essential small engine maintenance skill will help you improve your mower’s performance, ensure reliable operation, and extend its lifespan.