mxu 400 Manuel atelier : Page 43

                                                                     2. Place the valve cover on the Surface Plate covered
                                                              with #400 grit wet-or-dry sandpaper. Using light
                                                              pressure, move the valve cover in a figure eight
                                                              motion. Inspect the sealing surface for any indica-
                                                              tion of high spots. A high spot can be noted by a
                                                              bright metallic finish. Correct any high spots
                                                              before assembly by continuing to move the valve
                                                              cover in a figure eight motion until a uniform
                                                              bright metallic finish is attained.

                                                                           ! CAUTION
                                                          Do not remove an excessive amount of the sealing
                                                          surface or damage to the camshaft will result.
                                                MD1211
                                                          Always check camshaft clearance when resurfacing
    A. Starting with the top ring, slide one end of the   the valve cover.
       ring out of the ring-groove.
    B. Remove each ring by working it toward the
       dome of the piston while rotating it out of the
       groove.

                AT THIS POINT
To service piston, see Servicing Top-Side Compo-                                                                    3
nents sub-section.

                AT THIS POINT
To service center crankcase components only, pro-
ceed to Removing Left-Side Components.
                                                                                                          CC130D


      Servicing Top-Side                                                   ! CAUTION
         Components                                       Water or parts-cleaning solvent must be used in
                                                          conjunction with the wet-or-dry sandpaper or dam-
                                                          age to the sealing surface may result.
 NOTE: Whenever a part is worn excessively,
                                                          Removing Valves
cracked, or damaged in any way, replacement is
necessary.                                                  NOTE: Keep all valves and valve components as
                                                          a set. Note the original location of each valve set
VALVE ASSEMBLY
                                                          for use during installation. Return each valve set to
                                                          its original location during installation.
When servicing valve assembly, inspect valve seats,
valve stems, valve faces, and valve stem ends for pits,
burn marks, or other signs of abnormal wear.               1. Using a valve spring compressor, compress the
                                                              valve springs and remove the valve keepers.
 NOTE: Whenever a valve is out of tolerance, it               Account for an upper spring retainer.
must be replaced.

Cleaning/Inspecting Valve Cover

  NOTE: If the valve cover cannot be trued, the cyl-
inder head assembly must be replaced.

 1. Wash the valve cover in parts-cleaning solvent.




                                                                                                            CC994




                                                                                                            3-13