Royal Enfield CONSTELLATION 1958, Руководство по техническому обслуживанию мастерской

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SECTION C4
Service Operations with Engine in Frame
"Super Meteor"
1. Removal of Timing Cover
First place a tray under the engine to catch
the oil which will escape when the cover is
removed. Remove the timing side exhaust pipe
and the oil filler neck, by taking out the three
screws fixing it to the crankcase. Remove the
timing cover fixing screws. Draw off the timing
cover, tapping it lightly if necessary.
In refitting the cover, insert the two long
screws through the cover to locate the gasket.
See that the thrust washer is on the chain
tensioner sprocket spindle and that the neoprene
seal is in position on the oil feed plug. If the seal
is split or otherwise damaged, a new one should
be fitted, of the latest type, which is captive on
the feed plug. The feed plug is Part No. 42113
and the seal is Part No. 42114. If the plug is
damaged it should be renewed to ensure oil
pressure to the big end bearings.
The refitting of the cover will be facilitated if
the engine is turned gently forwards while the
cover is being put into place. This will help the
engagement of the pump worm with the pump
spindle and prevent damage to the gears.
Always fill the filter with clean oil before
refitting the timing cover and always take great
care not to damage the gasket where the section
is narrow.
To verify that the oil pumps are working
after replacing the timing cover, start the engine
and remove the oil filler cap so that the oil
return pipe can be seen. It may take several
minutes for all the oil passages to fill and the oil
to commence to circulate.
2. Valve Timing
The camshaft sprockets are keyed to the
camshafts so that the valve timing can only be
incorrect if the timing chain is incorrectly fitted.
The correct setting is obtained with the
marks stamped on the camshaft sprockets
facing each other inwards on the centre line and
the mark on the crankshaft sprockets pointing
vertically downwards. If it is necessary to
remove the sprockets see Subsections 23 and
24.
Remember that all three timing sprocket
fixing bolts have Left Hand Threads. While
tightening the camshaft bolts, the sprockets
should be held.
The correct valve timing at .012 in.
clearance is as follows:
Exhaust opens 75° before bottom dead centre.
Exhaust closes 35° after top dead centre.
Inlet opens 30° before top dead centre.
Inlet closes 60° after bottom dead centre.
3. Tappet Adjustment
The tappet clearance is adjusted by means of
a screw in the outer end of the rocker. Access to
the adjusting screws is obtained by removing
the covers of the rocker boxes.
The clearance between the end of the screw
and the valve stem cap should be nil or as little
as possible with the engine COLD.
To adjust the clearance, loosen the locknut
beneath the rocker arm, turn the screw with a
small spanner and re-tighten the locknut.
The adjustment for each valve should be
made with the corresponding valve of the other
cylinder fully open. This ensures that the tappet
is well clear of the ramp which is located on
either side of the cam to reduce valve noise.
If, after long service, the valve stem cap or
the rocker adjusting screw are found to be worn,
they should be renewed, as uneven thrust due to
the screw being in a different position after
adjustment may cause lateral movement of the
rocker giving rise to a sharp tapping noise.
4. Ignition Timing
The setting of the ignition depends upon the
position of the sprocket relative to the magneto
shaft.
To obtain access to the magneto sprocket it
is necessary to remove the timing cover (see
Subsection 1).
The sprocket is built into the automatic
advance device and is mounted on a smooth
taper on the magneto shaft. It is held in position
by a nut.
(Right Hand Thread.)
To remove the sprocket and auto-advance
device, unscrew the nut and this will draw the
sprocket off.
Before setting the timing remove the rotor
arm of the distributor and adjust the contact
breaker points to a clearance of .015 in. when
fully opened.
Because of the auto-advance mechanism,
the timing is normally in the "retard" position
when the engine is stationary. Rotate the two
Section C4 Page 1
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