Royal Enfield CONSTELLATION 1958, Руководство по техническому обслуживанию мастерской

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is loose) and split conical collets together in
order that they may be re-assembled with the
valve from which they were removed.
Deal similarly with the other valves in the
heads.
If the valve will not slide easily through the
valve guide, remove any slight burrs on the end
of the valve stem with a carborundum stone. If
the burrs are not removed and the valve is
forced out, the guide may be damaged.
12. Removal of Rockers
To remove the rocker, first take off the
cylinder head. Remove the hexagon plug on the
inner side and the rocker spindle may be drawn
out by means of a bolt screwed into the rocker
spindle, which is tapped 5/16" B.S.F.
On re-assembling make sure that the spring
washers are fitted on the sides of the rockers
nearest the centre of the engine and the plain
thrust washers on the outer sides.
13. Removal of Valve Guides
To remove the valve guides from the heads
two special tools are required which can easily
be made.
The first is a piece of tube with an internal
bore of not less than 7/8 in.
The second is a mandrel about 4 in. long
made from 9/16 in. diameter bar with the end
turned down to about 5/16 in. diameter for 1/2
in.
Support the cylinder head on the tube which
fits over the collar of the valve guide. Using the
mandrel force the guide out of the head with a
hand press or by using a hammer.
To fit a new guide, support the head at the
correct angle and use a hand press and the same
mandrel. If a hand press is not available and the
guide is replaced by a hammer, use a piece of
tube of 9/16 in. internal diameter to prevent
damage to the bore of the guide. If a valve guide
is removed for any reason, an oversize one
should be fitted in order to maintain the
interference. It is necessary to re-cut the valve
seat and grind in the valve after a guide has been
replaced. (See Subsection 18.)
A worn exhaust valve guide may give rise to
slight smoking from the exhaust pipe due to oil
passing down the valve stem on to the hot valve
head. This may also be caused or increased by
faulty operation of the breather.
14. Renewal of Sparking Plug Inserts
A steel thread insert is fitted into each
sparking plug bore to prevent damage to the
threads in the alloy cylinder heads.
This insert should not normally require
renewal but if it does become damaged, for
instance by a faulty plug, it can be pulled out
with a pair of pliers and a new one fitted.
To fit a new insert a special tool T.2142,
consisting of a piece of 7/16 in. diameter tube
or rod with a slot cut in the end is required.
The new insert is placed over the tool with
the tag engaging in the slot and it is screwed into
the plug hole in the cylinder head from the
outside until the last coil is 1 to 1.1/2 threads
below the top face. A reverse twist of the tool
will then break off the tag.
If the cylinder head has not been removed
from the engine, care must be taken not to drop
the end of the tag into the cylinder and in such a
case it is better to break off the tag with a pair of
long-nosed pliers.
15. Removal of Cylinders
When the cylinder heads have been removed
the cylinders can be lifted clear of the studs.
This should be done with the pistons at bottom
dead centre.
Section C4 Page 5
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