8. CYLINDER HEAD/VALVES MXU 500 IRS TORQUE VALUES Cylinder head bolt (1 4) 4.8 kgf-m (48 N-m) Apply engine oil to threads Cylinder head bolt (5 13) 2.3 kgf-m (23 N-m) Apply engine oil to threads Cylinder head nut 1 kgf-m (10 N-m) Cylinder head cover bolt 1 kgf-m (10 N-m) Breather separator bolt 1.3 kgf-m (13 N-m) Cam chain tensioner bolt 1.2 kgf-m (12 N-m) Tensioner sealing bolt 1 kgf-m (10 N-m) Rocker arm shaft 4.5 kgf-m (45 N-m) Cam chain guide pivot bolt 2 kgf-m (20 N-m) Water joint bolt 1.2 kgf-m (12 N-m) SPECIAL TOOLS Valve spring compressor A120E00040 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 White smoke from exhaust muffler · Compression too low · Worn valve stem or valve guide · Damaged valve stem oil seal Compression too low · Incorrect valve clearance adjustment Abnormal noise · Burned or bend valves · Incorrect valve clearance adjustment · Incorrect valve timing · Sticking valve or broken valve spring · Broken valve spring · Damaged or worn camshaft · Poor valve and seat contact · Worn cam chain tensioner · Leaking cylinder head gasket · Worn camshaft and rocker arm · Warped or cracked cylinder head · Poorly installed spark plug Compression too high · Excessive carbon build-up in combustion chamber 8-3