Periodic maintenance38ESU11450Safety is an obligation of the owner. Periodic inspection, adjustment, and lubrication will keepyour snowmobile in the safest and most efficient condition possible. The most important pointsof snowmobile inspection, adjustment, and lubrication are explained on the following pages.Maintenance, replacement, or repair of the emission control devices and systems maybe performed by any repair establishment or individual that is certified (if applicable).WARNINGEWS00340If you are not familiar with maintenance work, have a Yamaha dealer do it for you.PROPER PERIODIC MAINTENANCE OF YOUR SNOWMOBILE IS IMPORTANT IN ORDERTO ENJOY LONG, PLEASURABLE SERVICE. ESPECIALLY IMPORTANT ARE THE MAIN-TENANCE SERVICES RELATED TO EMISSION CONTROL. THESE CONTROLS NOTONLY FUNCTION TO ENSURE CLEANER AIR, BUT ARE ALSO VITAL TO PROPER EN-GINE OPERATION AND MAXIMUM PERFORMANCE. IN THE FOLLOWING PERIODICMAINTENANCE CHARTS, THE SERVICES RELATED TO EMISSION CONTROL AREGROUPED SEPARATELY. THESE SERVICES REQUIRE SPECIALIZED DATA, KNOWL-EDGE, AND EQUIPMENT. YAMAHA DEALERS ARE TRAINED AND EQUIPPED TO PER-FORM THESE PARTICULAR SERVICES.ESU11460Periodic maintenance chart for the emission control systemITEM REMARKSINITIAL EVERYPAGE1 monthor 800 km(500 mi)(40 hr)Seasonallyor4000 km(2500 mi)(200 hr)Spark plugs• Check condition.• Adjust gap and clean.• Replace if necessary.44* Valve clearance • Check and adjust valve clear-ance when engine is cold.Every 40000 km (25000mi) 49* Crankcase breathersystem• Check breather hose for cracksor damage.• Replace if necessary.—* Fuel filter • Check condition.• Replace if necessary. —* Fuel line• Check fuel hose for cracks ordamage.• Replace if necessary.—* Idle speed • Check and adjust idle speed. 45* Fuel injection • Adjust synchronization. —