1986-1991 Kawasaki 650 X-2 Service Manual, Page 57Get this manual
TOP END 57 Engine problems may be caused not only by carbon deposits and wear or damage to the engine itself, but also by poor quality fuel or oil, improper oil, incorrect gasoil mixture, improper fuelair mixture, or incorrect ignition timingWhenever knocking, pinging, piston slap, or other abnormal engine noise is heard, the cause should be determined as soon as possibleNeglect of proper maintenance will result in reduced engine power and may lead to accelerated wear, overheating, detonation, piston seizure, and engine destructionIf the cylinder compression is higher than the usable range, check the following: oCarbon buildup on the piston head and cylinder headclean off any carbon on the piston head and cylinder headOCylinder head gasket, cylinder base gasketsuse only the proper gasketsThe use of gasket of incorrect thickness wiHchange the compressionIf cylinder compression is lower than the usable range, check the following: oGas leakage around the cylinder headreplace the damaged gasket and check the cylinder head for warpoPistoncylinder clearance, piston seizureoPiston rings, piston ring grooves wear