2010-2012 PRO-RIDE RUSH Switchback RMK Service Manual, Page 90Get this manual
EngineCoolingExhaust Cylinder Measurement
Inspect cylinder for wear, scratches, or damageIf no damage is evident, measure the cylinder for taper and out of round with dial bore gaugeMeasure the bore 20mm from the top of the cylinder; in line with the piston pin and 90 to the pin to determine if the bore is out of roundRepeat the measurements at point just above the exhaust port and at point below the transfer portUse the chart below and record all measurementsNOTE: dial bore gauge is the only recommended tool to accurately measure cylinder bore diameter