2002 Yamaha Motorsports VK 540 lll Owners Manual - Page 50
2002 Yamaha Motorsports VK 540 lll Manual
Page 50 highlights
ESU00157 HIGH ALTITUDE ADJUSTMENTS Operating at high altitude reduces the performance of a gasoline engine, about 3% for every 305 m (1000 ft) of elevation. This is because there is less air as altitude increases. Less air means less oxygen available for combustion. Your snowmobile can be adjusted to overcome most of the problems found in high altitude riding. Carburetor adjustments are the most important. Less air at high altitude makes the fuel/air ratio too rich, which can cause poor performance. Common problems are hard starting, bogging, and plug fouling. Follow the Main Jet Setting chart which is available at an authorized Yamaha dealer carefully. Proper carburetion adjustments will correct the fuel/ air ratio. Remember: less air at higher altitude means there is less horsepower available, even with proper carburetion. Expect acceleration and top speed to be reduced at higher altitudes. To overcome operating with less power at high altitudes, your snowmobile may also require different clutch and driveline settings to avoid poor performance and rapid wear. If you plan to operate your snowmobile at an altitude different from the area where you bought your machine, be sure to consult your Yamaha dealer. He can tell you if there are any changes necessary for the altitude where you plan to ride. CAUTION: The drive chain gears and V-belt clutch should be adjusted when operating over 900 m (3000 ft) high altitude. Consult a Yamaha dealer. 8-9