2011 Yamaha Motorsports RS Viking Professional Owners Manual - Page 48
2011 Yamaha Motorsports RS Viking Professional Manual
Page 48 highlights
Periodic maintenance and adjustment ESU13470 Tool kit The service information included in this manual and the tools provided in the owner's tool kit are intended to assist you in the performance of preventive maintenance and minor repairs. However, additional tools such as a torque wrench may be necessary to perform certain maintenance work correctly. 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 plugs because heat and deposits will cause any spark plug to slowly break down and erode. Consult a Yamaha dealer before changing to a different type of spark plug. Specified spark plug: Manufacturer: NGK Model: CR8E EWS00710 1. Tool kit ECS00960 NOTICE Before starting the engine, make sure that the tools are properly seated in their holder. WARNING Be sure to use the specified spark plug and spark plug cap. Otherwise, the T.O.R.S. may not work properly. Spark plugs are produced in several different thread lengths. The thread length or reach is the distance from the spark plug gasket seat to the end of the threaded portion. If the reach is too long, overheating and engine damage may result. If the reach is too short, spark plug fouling and poor performance may result. Also, if the reach is too short, carbon will form on the exposed threads resulting in combustion chamber hot spots and thread damage. Always use a spark plug with the specified reach. Spark plug reach: 19.0 mm (0.75 in) TIP 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. ESU11783 Checking the spark plugs The spark plugs are important engine components and are easy to inspect. The condition of the spark plugs 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-tolight tan color for a snowmobile that is being ridden normally. If any spark plug shows a 42