CYLINDER HEAD—E.6 When  carrying  out  a  top  overhaul  only,  examine  the valve springs carefully with particular regard to squareness     of     ends     and     pressures     developed     at specified  lengths,  the  details  of  which  can  be  found  in the Technical Data Section. Rocker Shaft Assembly To Dismantle:— 1. Remove the circlips and washers from each end of the rocker shaft. 2. Withdraw   the   rocker   levers,   springs   and   support brackets from the shaft. 3. Remove the locating screw from the rocker oil feed connection  and  withdraw  the  connection    from    the shaft.    Wash  all  parts  thoroughly  in  cleaning  fluid. Examine  the  rocker  lever  bores  and  shaft  for  wear. The   rockers   should   be   an   easy   fit   on   the   shaft without excessive side play. To Reassemble 1. Fit  the  oil  feed  connection  to  the  rocker  shaft  and secure  with  the  locating  screw,  ensuring  that  the screw enters the locating hole in the shaft. 2. Refit   the   support   brackets,   springs,   and   rocker levers  to  the  shaft  in  the  order  shown  in  Fig.  E.2. The    support    brackets    are    interchangeable    and when   fitting   them   ensure   that   the   securing   stud holes  are  to  the  right  viewing  the  shaft  from  the front  end,  with  each  pair  of  rockers  inclined  away from each other at the valve end. 3. Fit  the  securing  washer  and  circlip  at  each  end  of the rocker shaft. Push Rods Check the push rods for straightness.  If any are bent, fit replacement push rods. To  fit  a  replacement  push  rod,  (excepting  numbers  1 and    8)    with    the    rocker    shaft    assembly    in    position proceed as follows:— 1. Ensure that the valve concerned is closed. 2. Slacken  off  the  valve  adjusting  screw  and  slide  the rocker   lever   sideways   until   the   push   rod   can   be withdrawn from the engine. 3. Fit   the   new   push   rod   and   re-adjust   the   valve clearance. To  fit  a  replacement  push  rod  to  numbers  1  and  8 tappets proceed as follows :— 1. Ensure that the valve concerned is closed. 2. Slacken off the valve adjusting screw. 3. Remove the circlip and washer securing the rocker lever  to  the  shaft  and  remove  the  lever  from  the shaft.    The  push  rod  can  now  be  withdrawn  from the engine. 4. Fit   the   replacement   push   rod.      Refit   the   rocker lever, washer and circlip to the rocker shaft. 5. Re-adjust the valve clearance. Fig. E.9. Valve Cap Sealing Arrangement To Re-Assemble the Cylinder Head 1. Ensure  that  the  cylinder  head  and  valves  etc.    are perfectly clean. 2. Lightly    oil    the    valve    stems    to    provide    initial lubrication. 3. Insert each valve in its correct bore. 4. Fit the valve oil deflector rubbers with the open end towards the cylinder head.