8-1ESU049608-PERIODIC MAINTENANCESafety is an obligation of the owner. Periodic inspection, adjustment, and lubrication willkeep your snowmobile in the safest and most efficient condition possible. The most impor-tant points of snowmobile inspection, adjustment, and lubrication are explained on the fol-lowing pages.Maintenance, replacement, or repair of devices and systems related to emissionscontrol may be performed by any repair establishment or individual that is certified(if applicable).WARNING@If you are not familiar with maintenance work, have a Yamaha dealer do it for you.@PROPER PERIODIC MAINTENANCE OF YOUR SNOWMOBILE IS IMPORTANT INORDER TO ENJOY LONG, PLEASURABLE SERVICE. ESPECIALLY IMPORTANT ARETHE MAINTENANCE SERVICES RELATED TO EMISSIONS CONTROL. THESE SER-VICES NOT ONLY ENSURE CLEANER AIR, BUT ARE ALSO VITAL TO PROPERENGINE OPERATION AND MAXIMUM PERFORMANCE. IN THE FOLLOWING PERI-ODIC MAINTENANCE CHARTS, THE SERVICES RELATED TO EMISSIONS CONTROLARE GROUPED SEPARATELY. THESE SERVICES REQUIRE SPECIALIZED DATA,KNOWLEDGE, AND EQUIPMENT. YAMAHA DEALERS ARE TRAINED AND EQUIPPEDTO PERFORM THESE PARTICULAR SERVICES.ESU04970Periodic maintenance chart for the emission control systemCD-31EItem RemarksPre-operationcheck(Daily)Initial1 monthor800 km(500 mi)(40 hr)EveryPageSeasonallyor4,000 km(2,500 mi)(200 hr)Spark plugsCheck condition.Adjust gap and clean.Replace if necessary. 8-7–8-8∗ Valve clearanceCheck clearance.Adjust clearance when engineis cold.Every 40,000 km (25,000 mi) 8-11∗ Crankcase breathersystemCheck breather hose forcracks or damage.Replace if necessary.∗ Fuel filter Check condition.Replace if necessary. ∗ It is recommended that these items be serviced by a Yamaha dealer.