2008 Arctic Cat DVX 250 / 250 Utility ATV Service Manual, Page 39Get this manual
2Acceptable width range must be within specificationsMeasuring Valve Guide (Inside Diameter) 1Insert snap gauge 12 way down into each valve guide bore; then remove the gauge and measure it with micrometer2Acceptable inside diameter range must be within specifications3If valve guide is out of tolerance, the cylinder head must be replacedCYLINDER HEAD ASSEMBLY NOTE: If the cylinder head cannot be trued, it must be replaced
Measuring Cylinder Head Distortion 1Remove any carbon buildup in the combustion chamber2Lay straightedge across the cylinder head; then using feeler gauge, check the distortion factor between the head and the straightedge3Maximum distortion must not exceed specifications
CleaningInspecting Cylinder Head 1Using non-metallic carbon removal tool, remove any carbon build-up from the combustion chamber making sure not to nick, scrape, or damage the combustion chamber or the sealing surface2Inspect the spark plug hole for any damaged threadsRepair damaged threads using "heli-coil" insert3Place the cylinder head on the surface plate covered with #400 grit wet-or-dry sandpaperUsing light pressure, move the cylinder head in figure eight motionInspect the sealing surface for any indication of high spotsA high spot can be noted by bright metallic finishCorrect any high spots before assembly by continuing to move the cylinder head in figure eight motion until uniform bright metallic finish is attainedMeasuring Camshaft Runout