2004 Official factory service manual for Yamaha YFZ450S ATV Quad., Page 171Get this manual
CYLINDER AND PISTON
2Measure: piston-to-cylinder clearance
MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM
aMeasure the cylinder bore "C" with cylinder bore gaugeNOTE: Measure the cylinder bore "C" in parallel to and right angles to the crankshaftThen, find the average of the measurementsCylinder bore "C" Taper limit "T" Out of round "R" "C"Maximum D