8. CYLINDER HEAD/VALVES MXU 550EXi /MXU500i Measure compressed force (valve spring) and installed length. Replace if out of specification. Standard: Inner: 3.5 kg (at 28.7 mm) Outer: 13 kg (at 31.43 mm) Measure the spring tilt. Replace if out of specification. Standard: Inner: 1.2 mm Outer: 1.2 mm ASSEMBLY Valve Spring Compressor Install the valve spring seats and oil seal. Be sure to install new oil seal. Lubricate each valve with engine oil and insert the valves into the valve guides. Install the valve springs and retainers. Compress the valve springs using the valve spring compressor, then install the valve cotters. · When assembling, a valve spring compressor must be used. · Install the cotters with the pointed ends facing down from the upper side of the cylinder head. Special tool: Valve Spring Compressor A120E00040 8-26