6. CYLINDER HEAD/VALVES STRYKER 125/150 TORQUE VALUES Cylinder head cover nut 1.21.6kg-m Cylinder head nut 2.0kg-m Valve clearance adjusting nut 0.9kg-m Exhaust muffler joint lock nut 1.82.5kg-m Exhaust muffler lock bolt 3.03.6kg-m Spark plug 1.11.7kg-m TROUBLESHOOTING · The poor cylinder head operation can be diagnosed by a compression test or by tracing engine top-end noises. Poor performance at idle speed Abnormal noise · Compression too low · Incorrect valve clearance adjustment Compression too low, hard starting · Sticking valve or broken valve spring or poor performance at low speed · Damaged or worn camshaft · Leaking cylinder head gasket · Worn cam chain guide · Loose spark plug · Worn camshaft and rocker arm · Worn, stuck or broken piston and piston rings Abnormal noisy piston · Worn or damaged cylinder and piston · Worn cylinder and piston Compression too high, overheating or knocking · Worn piston pin or piston pin hole · Excessive carbon build-up in cylinder head · Worn connecting rod small end bearing or on piston head Abnormal noisy piston rings · Worn cylinder and piston · Worn, stuck or broken piston rings · Incorrectly installed piston rings · Worn or damaged cylinder · Damaged cylinder and piston White smoke from exhaust muffler · Worn valve stem or valve guide · Damaged valve stem seal 6-3