2009 Polaris Scrambler 500 4x4 2x4 factory service manual, Page 46Get this manual
MAINTENANCE
DRIVE CHAIN ADJUSTMENT, CONCENTRIC SWINGARM
CAUTION: Never adjust or operate the vehicle with the rear drive chain too loose or too tight as severe damage to the transmission and drive components can resultBreak-In: It is extremely important to maintain proper chain tension to ensure the best possible chain lifeThere is chain break-in period of approximately 100 miles or two (2) tanks of fuelDuring this time chain tension should be watched very closely and loads to the chain should be kept lightChecking Deflection: Inspect chain deflection by slowly moving the ATV forward so any slack that may have previously been on the under part of the chain is now on the top side of the chainThe bottom part of the chain should be taught during inspectionMeasure the chain deflection as shown in the diagramDeflection should be approximately 38 in(10 mm)After inspection, again slowly move the ATV forward until all the chain slack is on the top side of the chain and inspect the deflectionRepeat this procedure several times to check different spots on the chainThe chain is correctly adjusted when the tightest portion of the chain itself has approximately 38in (10 mm) of deflectionIt's common characteristic of any chain to have one or more tight spots in the chainTherefore, it is extremely important to check chain deflection in several areas of the chain to ensure deflection is correct at the tightest point