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ASSEMBLY
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Fit the inlet rocker (2) and the exhaust rocker (3)
as indicated in the photo, inserting the 12x17x0.5
thrust washers (7) between the rockers and the
head cover, after you have lubricated them well
with engine oil.
Insert the rocker spindles (8) with the cutouts (A)
adjacent to the straight-through holes (B) for the
cylinder-head hold-down bolts, and with the end
containing a threaded hole facing outwards. This
hole is used for locating the rocker spindles in the
correct position using an M4 bolt.
4.16 CYLINDER HEAD
4.16.1 checks
Check the valve guides with a ø5H7 go/no-go gauge.
If the gauge is easily introduced into the guide, then
the guide must be replaced.
Check whether the valve stems show signs of wear,
scoring or damage. Then measure their diameter
and, if this value is below the limit, replace the
valve.
Minimum diameter 4.978mm
Check the valve stem/valve guide play. To do this,
locate the valve in its guide with the top surface of
the valve stem flush with the guide, and measure
the maximum radial oscillation of the valve head.
Play when new 0.08mm
limit of play 0.25mm
If the play exceeds this limit and the diameter of the
valve stem is within the prescribed limits, replace
the guide. Otherwise, replace both parts, unless the
diameter of the guide is in tolerance, in which case
only the valve is to be replaced.
Check the wear and the sealing surface of the valve
seats. To do this, apply a thin layer of engineer’s
Prussian blue to the contact area of the valve with
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