Royal Enfield CONSTELLATION 1958, Workshop Maintenance Manual

Page: 37 / 106

27. Removal of the Tappets and Guides
It is only necessary to remove the tappets
and guides if they have become worn.
Remove the cylinder heads and barrels.
(Subsections 10 and 15.)
Extract the tappet guides, using Special Tool
No. E.5790, having heated the case first.
The guides are made from Nickel Chrome
Alloy Iron and if a guide should break while
removing it, it can be withdrawn with a pair of
pliers if the crankcase is heated locally with a
blowlamp. Otherwise it is necessary to dismantle
the crankcase and drive the tappet and guide out
from underneath using a heavy bar in the cam
tunnel.
The guide should have an interference of
.0015 to .0025 in. in the crankcase and can be
driven in with a bronze drift, care being taken
when the guide is nearly home to avoid breaking
the collar.
When replacing the exhaust valve tappet
guides care must be taken to ensure that the
groove in the timing side exhaust guide comes
opposite the hole to the timing chest otherwise
flooding of the push rod hole in the cylinder will
occur causing over-oiling.
If a tappet guide is taken out it should be
replaced by an oversize one.
28. Dismantling the Breathers
If the breathers are not operating efficiently,
they may cause pressure in the crankcase,
instead of a partial vacuum, giving rise to
smoking or over-oiling.
See that the discs and backplate of the
breather on the crankcase immediately below
the left-hand cylinder are clean and undamaged,
and that the discs are seating properly.
When reassembling the breather, apply
jointing compound sparingly to the back of the
steel plate, taking great care to keep the
compound away from the discs and seatings.
Where fitted, the breather which operates
through the end of the crankshaft, may be
inspected by removing the slotted plug from the
head of the rotor retaining bolt. (See Fig. 8.)
29. Removal of the Clutch
Remove the engine sprocket and clutch
sprocket together as described in Subsection 26.
To remove the clutch hub, hold the clutch
with Special Tool No. E 4871 and remove the
centre retaining nut and washer with a box
spanner.
The hub can then be withdrawn from the
shaft with Special Tool No. E.5414.
30. Removal of the Final Drive Sprocket
Remove the clutch as described in
Subsection 29.
Remove the primary chain tensioner.
Remove the rear half of the primary chain
case by taking out three socket screws.
Remove the grub screw locking the final
drive sprocket nut.
Hold the sprocket and remove the nut (Right
Hand Thread). The sprocket can then be
withdrawn.
31. Removal of the Engine Bearing Housing
Felt Washer
(Engines prior to SMSA 6964)
Remove the engine sprocket, clutch and rear
half of the primary chain case.
The felt washer is located in the steel
housing at the back of the chain case.
Great care must be taken not to nip the felt
washer behind the sprocket on re-assembly as
this would make the engine very stiff to turn
over and would damage the washer and allow
leakage from the crankcase.
On Engine SMSA 6964 et seq a neoprene oil
seal is fitted and the above does not apply.
32. Oil Pipe Unions
The oil feed to the rocker gear is through
pipes from unions at the back of the crankcase
below the cylinder base to unions on the
cylinder heads.
The tapped holes into which the unions
screw into the aluminium are fitted with steel
wire inserts to prevent the threads in the
Section C11 Page 8
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