2007-2008 Polaris IQ Snowmobiles Service Manual, Page 144Get this manual
Engine and Cooling Systems DisassemblyAssembly Process2008 800 CFI Cylinder HeadCylinderPistons 1234567Remove the coolant from the engine using siphon, wet dry vac, or drain panRemove the air box, exhaust pipe and resonator from the engine compartmentRemove the high tension wires and spark plugs from the cylinder headRemove the thermostat housing outlet cooling hose from the housingLoosen all, then remove all head cover fastenersClean the fastener threads to remove any thread locking residueDiscard the head cover and cylinder head o-ringsAlways use new o-rings during assemblyInspect the cylinder headcombustion domes for any damageMeasure cylinder head flatnessReplace cylinder head if requiredIf only the cylinder is going to be removed, remove the fuel rail from the upper fuel injectorsSee "CFI Fuel Rail Injector(s) RemovalInstallation" on page 4.30Loosen all, then remove the cylinder boltsClean the bolt threads to remove any thread locking residueCarefully pull the cylinder upwards taking care not to drop the pistons and rods abruptly against the crankcaseRemove the cylinder base gasketUse gasket scraper to clean the gasket residue from the crankcase and cylinder baseInspect the cylinder wallsNicasil cylinders can only be lightly honedDamage that cannot be removed with light hone requires cylinder replacement or re-chromingInspect the crankcase and cylinder mating surfaces for warpingThe assembly process is the reverse of disassemblyAlways use new gaskets and o-rings during assemblyLiberally coat the inside of each cylinder bore and the outside of each piston with Polaris two-stroke engine oilWhen installing piston into cylinder, verify each piston ring opening is located at each piston ring locating pinSqueeze the top ring, then carefully slide the cylinder over the compressed ringDo the same with the bottom ringFollow the torque specifications and torque sequences located at beginning of chapter when tightening fasteners91011