2009 Polaris Sportsman 850 XP EFI EPS Service Manual, Page 123Get this manual
ENGINE Combustion Chamber
1Clean all accumulated carbon deposits from combustion chamber and valve seat area4Drive or press new guides from camshaft side of head to proper installed heightNote difference between intake and exhaust guide height belowIntake Valve Guide Height: 8.939.43 mm
NOTE: Carbon Clean Fuel Treatment (2871326) can be used to help remove carbon depositsIMPORTANT: Do not use metal scraper, coarse wire brush, or abrasive cleaners to clean the cylinder headDamage may result2Visually inspect cylinder head gasket surface and combustion chamber for cracks or damagePay close attention to the areas around spark plug and valve seats