8-88EBU23211Checking the spark plugThe spark plug is an important engine component,which is easy to check. Since heat and depositswill cause any spark plug to slowly erode, the sparkplug should be removed and checked in accor-dance with the periodic maintenance and lubrica-tion chart. In addition, the condition of the sparkplug can reveal the condition of the engine.To remove the spark plug1. Remove the spark plug cap.2. Remove the spark plug as shown, with thespark plug wrench included in the owner’s toolkit.To check the spark plug1. Check that the porcelain insulator around thecenter electrode of the spark plug is a medi-um-to-light tan (the ideal color when the ATVis ridden normally).NOTE:If the spark plug shows a distinctly different color,the engine could be operating improperly. Do notattempt to diagnose such problems yourself. In-stead, have a Yamaha dealer check the ATV.1. Spark plug cap1. Spark plug wrench
