2008-2010 Kawasaki KFX450R Factory Service Manual, Page 182Get this manual
ENGINE TOP END 5-21 Cylinder Head
Problem The cylinder compression is higher than the usable range Diagnosis Carbon accumulation on piston and in cylinder head (combustion chamber) is suspected due to damaged valve stem or piston oil ringsIncorrect cylinder head gasket thicknessDamaged auto-decompressor spring or decompressor do not move smoothlyExhaust gas leakage around cylinder headIncorrect seating surface of valveValve clearance is too narrowPistoncylinder clearance is too widePiston seizureBad condition of piston ring andor piston ring groovesAuto-decompressor do not move smoothlyRemedy (Action) Remove the carbon deposits and replace damaged parts if necessary
Replace the gasket with standard oneReplace the spring or auto -decompressorReplace the damaged gasket and check cylinder head warpRepair seating surface if possibleAdjust the valve clearanceReplace the piston andor cylinder Inspect the cylinder and piston; repair or replace them if necessaryReplace the piston andor the piston ringsReplace the auto-decompressor