2004 Official factory service manual for Yamaha YFZ450S ATV Quad., Page 150Get this manual
CAMSHAFTS EBS00228
CHECKING THE TIMING CHAIN TENSIONER 1Check: chain tensioner rod Damagewear Replace2Check: timing chain tensioner play
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aWhile pressing the tensioner rod lightly with fingers, use thin screwdriver and wind the tensioner rod up fully clockwisebWhen releasing the screwdriver by pressing lightly with fingers, make sure that the tensioner rod will come out smoothlycIf not, replace the tensioner assemblyLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLL