2012 Sportsman 400/500 and EFI Tractor Service Manual 9923412, Page 82Get this manual
ENGINE 7Place new guide in the valve guide installation tool and press guide in to proper depthCheck height of each guide above the cylinder head (A)12Place 46o cutter on the pilot and make light cut
Valve Guide Installed Height Valve Guide Height: .689.709" (17.518.0 mm) NOTE: The guide can also be driven in to the proper depthInspect the guide closely for cracks or damage if driver is usedReaming The Valve Guide 8Allow cylinder head to cool to room temperatureApply cutting oil to the reamerGuides should be reamed from the valve spring side of the cylinder headReam each guide to size by turning the reamer clockwise continuallyContinue to rotate reamer clockwise during removal of the tool13Inspect the cut area of the seat If the contact area is less than 75 of the circumference of the seat, rotate the pilot 180o and make another light cut If the cutter now contacts the uncut portion of the seat, check the pilotLook for burrs, nicks, or runoutIf the pilot is bent it must be replaced If the contact area of the cutter is in the same place, the valve guide is distorted from improper installation and must be replacedBe sure the cylinder head is at the proper temperature and replace the guide If the contact area of the initial cut is greater than 75, continue to cut the seat until all pits are removed and new seat surface is evidentNOTE: Remove only the amount necessary to repair the seat surfaceof material