2009 Yamaha Motorsports V Star 250 Owners Manual - Page 44
2009 Yamaha Motorsports V Star 250 Manual
Page 44 highlights
PERIODIC MAINTENANCE AND ADJUSTMENT 3. Check each spark plug for electrode erosion and excessive carbon or other deposits, and replace it if necessary. Specified spark plug: NGK/C6HSA DENSO/U20FS-U 2. Clean the surface of the spark plug gasket and its mating surface, and then wipe off any grime from the spark plug threads. 3. Install the spark plug with the spark plug wrench, and then tighten it to the specified torque. Tightening torque: Spark plug: 12.5 Nm (1.25 m·kgf, 9.0 ft·lbf) 1. Spark plug wrench 7 To check the spark plugs 1. Check that the porcelain insulator around the center electrode on each spark plug is a medium-tolight tan (the ideal color when the vehicle is ridden normally). 2. Check that all spark plugs installed in the engine have the same color. TIP If any spark plug shows a distinctly different color, the engine could be operating improperly. Do not attempt to diagnose such problems yourself. Instead, have a Yamaha dealer check the vehicle. To install a spark plug 1. Measure the spark plug gap with a wire thickness gauge and, if necessary, adjust the gap to specification. TIP If a torque wrench is not available when installing a spark plug, a good estimate of the correct torque is 1/4-1/2 turn past finger tight. However, the spark plug should be tightened to the specified torque as soon as possible. 4. Install the spark plug cap. 1. Spark plug gap Spark plug gap: 0.6-0.7 mm (0.024-0.028 in) 7-9