PERIODIC MAINTENANCE AND ADJUSTMENT7-11123456789To check the spark plug1. Check that the porcelain insulatoraround the center electrode of thespark plug is a medium-to-light tan(the ideal color when the vehicle isridden normally).TIPIf the spark plug shows a distinctly dif-ferent color, the engine could be oper-ating improperly. Do not attempt todiagnose such problems yourself. In-stead, have a Yamaha dealer checkthe vehicle.2. Check the spark plug for electrodeerosion and excessive carbon orother deposits, and replace it ifnecessary.3. Measure the spark plug gap with awire thickness gauge and, if nec-essary, adjust the gap to specifica-tion.To install the spark plug1. Clean the surface of the spark pluggasket and its mating surface, andthen wipe off any grime from thespark plug threads.2. Install the spark plug with thespark plug wrench, and then tight-en it to the specified torque.TIPIf a torque wrench is not available wheninstalling a spark plug, a good estimateof the correct torque is 1/4–1/2 turnpast finger tight. However, the sparkplug should be tightened to the speci-fied torque as soon as possible.3. Install the spark plug cap.1. Spark plug wrench1Specified spark plug:NGK/DR8EADENSO/X24ESR-U1. Spark plug gapSpark plug gap:0.6–0.7 mm (0.024–0.028 in)1Tightening torque:Spark plug:18 Nm (1.8 m·kgf, 13 ft·lbf)
