2002 Yamaha Motorsports VMAX Owners Manual - Page 61
2002 Yamaha Motorsports VMAX Manual
Page 61 highlights
PERIODIC MAINTENANCE AND MINOR REPAIR NOTE: If any spark plug shows a distinctly different color, the engine could be defective. Do not attempt to diagnose such problems yourself. Instead, have a Yamaha dealer check the motorcycle. @ @ 1. Spark plug wrench 2. Remove the spark plug as shown, with the spark plug wrench included in the owner's tool kit. 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 motorcycle is ridden normally). 2. Check that all spark plugs installed in the engine have the same color. 3. Check each spark plug for electrode erosion and excessive carbon or other deposits, and replace it if necessary. Specified spark plug: DPR8EA-9/NGK or X24EPR-U9/DENSO a. Spark plug gap To install a spark plug 1. Measure the spark plug gap with a wire thickness gauge and, if necessary, adjust the gap to specification. Spark plug gap: 0.8-0.9 mm (0.03-0.04 in) 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. 6 6-10