2007 Yamaha Motorsports Nytro Owners Manual - Page 60

E_8gg.book Page 5 Thursday, March 16, 2006 4:23 PM A ESU03761 Tool kit The owner's tool kit has the tools which are sufficient for most periodic maintenance and minor repairs. A torque wrench is also necessary to properly tighten nuts and bolts. 1 Tool kit B È RS90N/RS90NR/RS90M/RS90MS É RS90R/RS90GT/RSG90/RSG90GT CAUTION: @ Before starting the engine, make sure that the tool kit is properly seated in its holder and is securely fastened. @ NOTE: @ If you do not have a torque wrench available during a service operation requiring one, take your snowmobile to a Yamaha dealer to check the torque settings and adjust them if necessary. @ ESU03681 Checking the spark plugs The spark plug is an important engine component and is easy to inspect. The condition of the spark plug can indicate the condition of the engine. Check the coloration on the white porcelain insulator around the center electrode. The ideal coloration at this point is a medium to a light tan color for a snowmobile that is being ridden normally. If a spark plug shows a distinctly different color, there could be something wrong with the engine. For example, a very white center electrode porcelain color could indicate an intake track air leak or carburetion problem for that cylinder. Do not attempt to diagnose such problems yourself. Instead, take the snowmobile to a Yamaha dealer for inspection and possible repairs. You should periodically remove and inspect the spark plug because heat and deposits will cause a spark plug to slowly break down and erode. Consult a Yamaha dealer before changing to a different type of spark plug. 8-5