2010 Polaris Sportsman 850 Service Manual, Page 129Get this manual

2010 Polaris Sportsman 850 Service Manual, Page 129

ENGINE Combustion Chamber 1Clean all accumulated carbon deposits from combustion chamber and valve seat area4Drive or press
the combustion chamber sideDrive or press old valve guides out of cylinder headExhaust Valve Guide Height: 6.757.25 mm CAUTION
Replacement of valve guides requires an oven, special equipment and experience to do the job correctlyIf you are unsure of
your ability to do the repair professionally it is best to sublet the labor to competent machinistValve seat reconditioning
is required when valve guides are replaced CAUTION The cylinder head can be easily damaged if the procedure is done carelessly3Apply
90 weight oil to outside of new valve guides5Ream or hone new valve guides to size to obtain specified stem-to-guide clearanceReam
from combustion chamber side of head CAUTION Do not tilt the reamer while reaming the guideAlways rotate the reamer in clockwise