Royal Enfield INTERCEPTOR 1965 User manual
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WORl{SHOP
MAINTENANCE
MANUAL
FOR THE
736
c.c.
''INTERCEPTOR''
MOTOR CYCLE
TRADE
lt#AR/C
•
1
M,ADI'
LIKE
A
GIIN
1
THE
ENFIELD
CY
-
CLE
CO
-
MP
-
ANY
LIMITED
HEAD
OFFICE
AND
WORKS:
REDDITCH, WORCESTERSHIRE, ENGLAND
Telephone:
Redditch
4222 (9
lines)
S.T.D. RE9. 4222
Telegrams
:
"
Cycles,
Redditch
"
www.hitchcocksmotorcycles.com
1965
"INTERCEPTOR" U.K. MODEL
1965
T.T. "INTERCEPTOR" U.S.A. MODEL
(Frontispiece)
www.hitchcocksmotorcycles.com
Royal
Enfield
"Interceptor"
Workshop Manual
Page
TECHNICAL
DATA
5
ENGINE
SPECIFICATION
6-10
1.
Engine
...
6
2. Cylinder
Heads
6
3.
Cylinders 6
4.
Pistons
6
5.
Connecting
Rods
6
6.
Crankcase
6
7.
Crankshaft
and
Flywheel 6
8.
Main
Bearings 6
9.
Camshafts
6
10. Valves 7
11. Valve
Gear
7
12.
Timing
Drive
7
13.
Ignition
and
Lighting System 7
14.
Carburetters
.. . 8
15.
Air
Filter
8
16.
Lubricat
i
on
System ... 8
17.
Breather
8
18.
Gearbox
8
Oil
Pump
Diagrams
... 9
19.
Clutch
10
SERVICE
OPERATIONS
WITH
ENGINE
IN
FRAME
10-19
20.
Removal
of
the
Timing Cover
10
21. Valve
Timing
10
22.
Tappet
Adjustment
... 10
23.
Removal
of
the
Camshafts
...
11
24.
Ignition
Timing
-
11
25.
Primary
Chain
Adjustment
... 12
26.
Timing
Chain
Adjustment
... 12
27.
Magneto
Chain
Adjustment
12
· 28.
Removal
of
the
Dual
Seat
and
Rear
Mudguard
...
12
29.
Removal-of
the
Petrol
Tank.
_.. 12
30.
Removal
and
Refitting
of
the
Cylinder
.Head
13
31.
Reniovai
of
the
Valves
13
32.
Removal
·
of
the
Rockers 14
33.
Removal
of
the
Valve Guides 14
34.
Removal
of
Sparking Plugs 14
35.
Removal
of
the
Cylinders 14
36.
Removal
of
Pistons 14
37.
Decarbonising
14
38
.
Grinding
~
in
Valves
15
39.
Reassembly
afterDecarbonising 15
40.
Cleaning
the
Oil
Filters 16
41.
Overhaul
of
Oil
Pumps
16
42.
Removal
of
the
Timing Chains 17
43.
Removal
of
Pump
Worm
and
Timing
Sprocket
17
44
.
Removal
of
Camshaft
Sprockets 17
45.
Removal
of
the
Magneto
...
17
46
.
Removal
of
the
Engine
and
Clutch
Sprockets
17
47.
RemovalofTappetsandGuides
17
48.
Dismantling
the
Breathers ... 17
49.
Removal
of
the
Clutch 17
50.
Removal
of
Final
Drive
Sprocket
18
51.
OilSealBehindEngineSprocket
18
52. Oil
Pipe
Unions
18
53.
Rocker
Oil
Feed
Relief Valve
18
54.
Fitting
the
Alternator
18
SERVICE
OPERATIONS
WITH
ENGINE
REMOVED
19-21
55.
Removal
of
the
Engine
Gear-
box
Unit
from
the
Frame
...
19
56.
Removal
of
the
Gearbox
19
57.
Dismantling
the
Crankcase
...
19
LIST OF CONTENTS
58.
Main
Bearings
59.
Fitting
the Connecting
Rods
Page
20
20
20
21
21
60. Reassembly
of
Crankcase
61
.
Crankshaft
Plugs
62.
Pump
Worm
Threads
GEARBOX
AND
CLUTCH
63
. Description
of
the
Clutch
64. Description
of
the
Gearbox
.. .
65. Removal
of
the
Gearbox
66.
To
Dismantle
the
Gearbox
...
67. Removal
of
the
Ball Races ...
Operation
of
Gears
...
68.
Change-Gear
Menchanism
.. .
69. Reassembling
the
Gearbox
.. .
21-26
21
22
22
22
22
23
24
24
70. Dismantling
and
Reassembling
the Clutch
71.
Adjustment
of
Clutch
Control
24
24
25
26
26
Exploded view
of
Gearbox
...
72. Adjustment
of
Neutral
Finder
73.
Gearbox
Oil Level
AMAL
MONOBLOC
CARBURETTER
74. General
Description
75.
Tuning
the Carburetter(s)
Exploded View
of
Monobloc
27-31
27
28
Carburetter
... 29
76.
Tuning
Sequence with
Two
Carburetters
...
77. Dismantling
Carburetter
30
30
78. Causes
of
High
Petrol
Con-
sumption
LUCAS
TWIN
-
CYLINDER
MAGNETO
79. General
80. Lubrication
81. Adjustments
...
82. Cleaning
83.
High
Tensi
on
Cables
31
31-33
31
31
32
32
32
84. Renewing
Timing
Control
Cable
(Manual
Control)
32
32
85.
Contact
Breaker Springs
86. Servicing. Testing
Magneto
in Position
on
Engine
33
87.
Automatic
Advance
Mechanism
33
GENERATOR/RECTIFIER
CHARGING
SET
88. General (6-volt Sets)...
89. Maintenance
34-36
34
36
BATTERY
37
90. General
37
91. Technical
Data
37
92. Filling
and
Soaking
Batteries
37
HEAD
AND
TAIL
LAMPS
38
-
39
93.
Headlamp
38
94. Lucas Light
Unit
38
95.
ReplacingLightUnitandBulb
38
96.
Parking
Lights (Early Models
with Casquettes)
97. Tail Light
FRAME
98. Description
of
Frame
99. Steering
Head
Races
100.
Removal
of
Rear
Suspension
39
39
40-42
40
41
Unit
..
.
41
101. Servicing
Rear
Suspension
Units
41
102.
Removal
of
Swinging
Arm
Chain
Stays
...
42
103. Centre Stand
104. Wheel Alignment
105. Lubrication
FRONT
FORK
...
106. Description
107. Operation
of
the
Fork
108. Dismantling the
Fork
to
Replace Spring, Oil Seal
or
Bearing Bushes
109. Springs
110. Reassembly
of
Parts
111. Steering
Head
Races
112. Removal
of
Complete Fo
rk
113. Lubrication
Page
42
42
42
43-46
43
44
44
45
45
45
46
46
FRONT
WHEEL 47-50
114. Removal from
Fork
47
115. Removal
of
Brake Cov
er
Plate Assembly 47
116. Replacing Brake Linings 47
117. Removal of Brake Operating
Cam(s) 47
11
8.
Removal
of
Hub
Spindle and
Bearings
47
119.
Hub
Bearings 48
120. Fitting Limits for Bearings... 48
121. Refitting Ball Bearings 48
122. Reassembly
of
Brake Shoes
and
Operating
Cam
into
Cover Plate 49
123. Final Assembly
of
Hub
before Replacing Wheel ... 49
124. Wheel Rim ... 49
lli
~~es
~
126. Wheel Building
and
Truing 49
127. Tyre .. . 49
128. Tyre Pressure 50
129. Lubrication 50
REAR
WHEEL
... 50-55
130. Description 50
131. Removal
and
Replacement
of
Main Portion
of
Wheel
for
Tyre Repairs, etc. 50
132. Removal and Replacement
of
Complete Wheel for access
to Brake 50
133
. Removal
of
Brake Shoes for
Replacement, etc. ... ...
51
134. Removal
of
Brake Operating
Cam...
52
135. Cush Drive
...
52
136. Removal
of
Ball Bearings ...
53
137.
Hub
Bearings
53
138. Fitting Limits for Bearings
53
139
RemovalofHubDrivingPins
54
140. Refitting Ball Bearings 54
141. Reassembly
of
Brake Shoes
and
Operating Cam into
Cover Plate 54
142. Centring
Cam
Housing 54
143. Final Reassembly
of
Hub
before Replacing Wheel ... 54
144. Wheel Rims 54
145. Spokes 54
146. Wheel Building
and
Truing
55
147. Tyre
55
148. Tyre Pressures 55
149. Lubrication 55
SPECIAL
TOOLS
56--60
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www.hitchcocksmotorcycles.com
Royal Enfield
"Interceptor"
Workshop Manual Page 5
Technical Data
" Interceptor " Engine
Cubic
Capacity
Stroke
...
Bore
Nominal
Nominal
Actual
736 c.c.
93
mm
.
71
mm.
70·92
mm
./2·792 in.
Rebore
to
·020 in. oversize when wear exceeds ·0065 in.
Compression
Ratio
.. . 8
to
I
or
7¼
to
1
Piston
Diameter-
Bottom
of
Skirt-
Fore
and
Aft
Top
Lands
... 2·788 in.
2·7635 in.
Skirt
is tapered
and
oval turned.
Piston
Rings-
Width-Plain
Rings ·0625/·0635 in.
Single Scraper
Ring
·1550/·1560 in.
Double
Scraper Rings ·0781/-0776 in.
Radial
lbickness
2·883/3·085 mm.
Gap
when
in
unworn Cylinder... ·015/·020 in.
Clearance
in
grooves ... ·001 /·003 in.
Renew
Piston
Rings when gap exceeds
rr
in.
Oversize
Pistons
and Rings available
+·020
in.
Piston
Boss
Internal
Diameter ·7498/·7500 in.
Gudgeon
Pin
Diameter
·7498/·7500 in.
Con.
Rod
Small
End
InternalDiameter ·7507/·7505 in.
Big
End
Internal
Diameter Con.
Rod
2·0190/2·0185 in.
Big
End
Internal
Dia
. Bearing Shells l ·8750/1·8755
in."
Crank
Pin
Diameter, Timing Side ... 1·8744/1·8740 in.
Crank
Pin
Diameter,
Driving Side ... 1·8741/1·8737 in.
Driving
Side
Main
Ball
Bearing-
Type
Outside
Diameter
Inside
Diameter
Width
Timing
Side
Main
Roller
Bearing-
.
Type
Outside
Diameter
Inside
Diameter
Width
Rocker
Inside
Diameter
Rocker
Bearing Inside Diameter
Rocker
Spindle Diameter ...
Inlet
Valve
Stem
Diameter ...
Exhaust
Valve
Stem
Diameter
Valve
Guide
Internal
Diameter
Valve
Guide
External Diameter
Hoffman
145
or
Rand
M-LJ45
85
mm.
45
mm.
19mm.
Hoffman
R145
or
Rand
M-LR45
85mm.
45mm.
19mm.
·5627/·5622 in.
·5622/-5617 in.
·5617/·5615 in.
·3430/·3425 in.
·3410/·3405 in.
·3437/·3447 in.
·6275/·6270 in..
Valve
Guide
Hole
in Cylinder Head
Dia
.
Tappet
Stem
Diameter
·625/·626 in.
·3743/·3740 in.
·3755/·3745 in.
1·0125/1·0130 in. ·
l·011
/1
·010 in.
Tappet
Guide
Internal Diameter ...
Tappet
Guide
External Diameter ...
Tappet
Guide
Hole
in CrankcaseDia.
Tappet
Clearance
with cold
engine-
Inlet
-
Exhaust
Inlet
Exhaust
Nil }
Normal
Nil
running
Nil
Continuous
.005, high-_speed
runrung
*Assumes ·0005 in.
"stretch"
of
eye
of
rod
and
cap
due
to
interference fit
of
bearing shells.
Valve Spring
Free
Length-
Inner
1½
in.
1-f!
in.
Outer
(Renew when reduced by
nr
in.)
Valve Timing with ·012 in. clearance. See Page
11
Camshaft Bearing External Diameter ·9095/·9085 in.
Camshaft Bearing Internal Diameter ·7505/·7495 in.
(Bored in position in crankcase.)
Cam
Lift-
Exhaust ...
Inlet
Valve Lift
(approx.)-
Exhaust ...
Inlet
Timing Sprocket
Camshaft Sprockets
Magneto Sprocket
Timing
Chain-Type
Length
Width
Pitch
Roller
Magneto
Chain-Type
Length
Width
Pitch
Roller
Magneto Speed
Points
Timing-Advanced
Engine Sprocket
Clutch Sprocket
Final Drive Sprocket
Primary
Chain-Type
Length
Width
Pitch
• Roller
Feed Oil
Pump-Speed
Sports-
·328 in.
Std
.
-·3125
in.
Sports-
·344 in.
Std.-·3125
in.
Sports-
·
328
in.
Std.-·3125
in.
Sports-
·344 in.
Std.-
·
3125
in.
12
Teeth
24
Teeth
19
Teeth
Single No. 110038 endless
66 Pitches
·
225
in.
·375 in.
·250 in.
Duplex No. 114500 endless
44 Pitches
8·64 mm.
8mm.
5mm.
Half
Engine Speed
·015 in.
# in. before T.D.C. (32°)
·
29
Teeth
56
Teeth
21
or 20 Teeth
... Duplex No. 114038 endless
92 Pitches
·628 in.
·375 in.
·250 in.
Piston Diameter ...
Stroke length
1/6 Engine Speed
·24975/·24950 in.
·5 in.
Return Oil
Pump-Speed
Piston Diameter
Stroke length ...
1/6 Engine Speed
·375/·3755 in.
·5
in.
Sparking
Plug-Lodge
2HLN. Champion N5
or
NAB,
or
KLG FE.75, Autolite AE2.
For
high speed
running
over long distances, use Lodge
3HLN,
Champion N3
or
NAl0,
or
KLG
FE.100, Autolite AE 901.
Diameter
Reach
Gap
...
14mm.
¾in.
·018/-022 in.
www.hitchcocksmotorcycles.com
Page 6 Royal Enfield
"Interceptor"
Workshop Manual
Engine
Specification
1. Engine
The
engine
is
an
even-firing vertical twin-
cylinder, having separate cylinders
and
heads and
fully enclosed pressure-lubricated overhead valve
gear.
It
has a dry
sump
lubrication
with the oil
tank
integral withthe crankcase
and
a massive one-
piece high-strength spheroidal graphite cast iron
crankshaft.
2.
Cylinder Heads
The
cylinder heads
are
die-cast from light
aluminium
alloy with ample finning
to
ensure
adequate
cooling.
The
exhaust pipe inserts are
cast-in
and
the valve inserts are
of
austenitic iron
and
are shrunk
in
so
that
they are replaceable.
The
large capacity induction
ports
are streamlined
and
blended to the valve seatings.
3. Cylinders
The
separate cast-iron cylinders have a nominal
bore
of
7l mm, the
stroke
being
93
mm.
The
cubic
capacity
of
the
engine is 736 c.c.
The
cylinder heads are located
on
the
cylinders by
hollow
dowels and
the
joint
between head and
barrel
is made by a split,
triangular
section steel
ring
which seats on a chamfer
at
the
top
end
of
the
cylinder barrel and stands
about
·005 in.
proud
of
the
joint
face.
The
push
rod
tunnels are sealed
by
washers
of
special
heat
and
oil resistant rubber
bonded
to
metal
and
fitting
in
recesses in the
cylinder head.
4.
Pistons
The
pistons are
made
of
low
expansion alu-
minium
alloy, heat treated
and
form
ground taper
and
oval. Standard
and
low
compression pistons
are
available; the former having approximately
½in. dome
and
the latter
about
fir
in. Each piston
carries two compression rings,
of
which the top
one
is chrome plated.
Standard
compression
pistons
are fitted with a special dual oil control
ring.
Low
compression pistons use a single
slotted
type ring.
Compression ratios are as
follows:-
Standard Pistons,
No
compression
plate-
8½
to
1.
Standard Pistons, I compression
plate-
8
to
I.
Standard Pistons, 2 compression
plates-
7½
to
1.
Low
Compression Pistons,
no
plate-
7¼
to
1.
Low
Compression Pistons, 1
plate-6·9
to
I.
Low CompressionPistons, 2
plates-6·6
to
1.
5. Connecting Rods
The
connecting rods are produced from stamp-
ings
of
Hiduminium RR56 light alloy. The little
end
bearings are
of
alloy direct
on
to the gudgeon
pin.
In
case
of
wear after long service the little
end
can
be bored
out
and
fitted with a bush,
but
this is rarely necessary. ·
The
big
end
bearings consist
of
white-metalled
steel liners which are renewable.
The
detachable
bearing caps are bolted to
the
connecting rods
by
means
of
high tensile socket screws,
the
heads
of
which are drilled for wiring.
6.
Crankcase
The
combined crankcase
and
oil
tank
is die-cast
from
light alloy
in
two halves, being split vertically.
7. Crankshaft
and
Flywheel
The
crankshaft is cast
in
one piece, integral
with the massive central flywheel, from high quality
spheroidal graphitic cast iron.
The
total weight is
approximately 24 lbs.,
and
all crankshafts are
dynamically balanced.
The
main
journals are ground,
and
the big end
journals
are ground
and
hand. lapped.
The
main
journal
on
the drive side
is
drilled through its
centre
for
the
crankcase breather.
8. Main Bearings
Heavy duty bearings are provided for the
crankshaft, the driving side being ball
and
the
timing side roller.
9. Camshafts
The
camshafts are machined from drop forged
steel stampings with the ·cams
and
bearings
hardened
and
ground.
The
cam profiles are
produced
to
give racing performance and, in order
to
obtain
the maximum efficiency, the usual
silencing
ramps
are omitted. Alternative cam-
shafts with quietening ramps are available for
riders who are prepared
to
sacrifice a little per-
formance in the interests
of
mechanical silence.
These were fitted
to
the
earlier engines.
The
camshafts are located
in
the crankcase and
www.hitchcocksmotorcycles.com
Royal Enfield
"Interceptor"
Workshop Manual Page 7
-
t
(I'---
➔
--
..
-----
►
--,,
EEO
PUMP
+ CRANKCASE.
LUBRICATION SYSTEM. Diagrammatic Arrangement
Fig. 2
run
in
bronze
bushes.
The
bushes
on
the nearside
are
pressed
into
detachable housings which
are
bolted
to
the
driving side crankcase.
This
enables
the
camshafts
to
be
changed,
if
so desired
for
tuning
purposes,
without the necessity
of
dismantling
the
crankcase.
10. Valves
The
inlet
valves are machined
from
stampings
of
special Silicon-Chrome Valve Steel
and
the
exhaust valves
are
of
High-Nickel-Chromium-
Tungsteri Valve Steel with the stems Stellite-tipped.
11. Valve Gear
The
valves
are
operated
from
the
camshaft
by
means
of
large,
flat-based, guided
tappets,
tubular
alloy
push
rods
with
induction
hardened
steel ends
and
overhead
rockers. Two compression springs
are
fitted
to
each
valve secured by Bullock
Type
split collets
locking
in
high strength
aluminium
collars.
The
springs are specially designed
to
give
a
variable
rate
on
compression.
12.
Timing Drive
The
camshafts are located in the crankcase
running
in
bronze
bushes. They are diiven by
an
endless chain from the timing sprocket on
the
crankshaft
and
the tightness
of
the chain
can be adjusted
by
means
of
the chain tensioner
in
the timing chest.
The
magneto
is driven by a separate endless
chain
from
the
rear
camshaft sprocket
in
the
timing chest.
The
tension
of
this chain is adjusted
by moving
the
magneto
fixing bolts in their slotted
holes.
A special slotted
bolt
securing the front cam-
shaft
sprocket
provides a drive
to
a tachometer
if
this is required. This drive can
be
fixed
to
an
aperture
provided
in
the timing cover, which is
otherwise covered by a small plate.
13. Ignition and Lighting System
The
ignition is supplied from a Lucas
K2F
magneto
and
the lighting
and
other
electrical
circuits
from
a
6-
or
12-volt
battery
which is
charged
through
a rectifier from a Lucas alternator.
www.hitchcocksmotorcycles.com
Page
8 Royal Enfield
"Interceptor"
Workshop Manual
The
alternator
is
housed in the primary chain-
case, the permanent magnet rotor being mounted
on
the
end
of
the crankshaft and the six coil stator
fixed
to
the back of the chaincase. When a 12-volt
battery
is used the "Zener
Diode"
regulation system
is employed. This ensures maximum charge rate
when
the battery voltage is low, cutting down to a
trickle charge
as
the voltage rises.
The
magneto
is
chain-driven from the inlet
camshaft
at
half engine speed and the timing
is
band
controlled from a lever on the handlebar on
the
earlier models, while later models have an
automatic
centrifugal control incorporated in the
magneto
sprocket.
14.
Carburetters
Twin
Amal Monobloc carburetters with a bore
of
1¼ in. are fitted as standard.
On
the earlier
models only the left-hand carburetter contained
a float chamber, the right-hand instrument being
fed
by
a short flexible connecting tube joining the
two
jet
holders. Later, carburetters with right-hand
float chambers became available and were used on
the
right-handside ofthe machine with the standard
left-hand float chamber on the left.
15. Air Filter
Provision is made for housing twin 5 in.
diameter Yokes Micro-Vee felt and gauze dry
filters
in
a compartment
of
the toolbox,
but
the use
of
these may reduce the maximum speed slightly.
16. Lubrication System
Lubrication is by the Royal Enfield
Dry
Sump
system which is entirely automatic and positive in
action.
The
oil tank
is
integral with the crankcase,
ensuring the full rate
of
circulation immediately
the
engine is started and rapid heating
of
the oil in
cold
weather.
There
are two positively driven piston type oil
pumps
running
at
¼engine speed, one
at
the rear
of
the
timing cover for pumping oil to the bearings
under
pressure and the other
at
the front for
returning
the oil from the crankcase
to
the tank.
The
return
pump has a capacity approximately
double
that
of
the feed
pump
which ensures
that
oil does
not
accumulate in the crankcase.
The
oil from the big ends drains into the bottom
of
the
crankcase and
is
prevented by a baflie from
being drawn up by the flywheel.
The
oil from the rocker bearings is squirted
through
a small hole in each"rocker on to the top
ends
of
the push rods.
It
then flows down the
push
rod
tunnels into the cam tunnels, where
it
lubricates the cams and tappets. Oil from the
rear
(inlet) cam tunnel is then returned direct to
the
oil
tank
through a drilled passage. Oil from
the
front
(exhaust) cam tunnel overflows into the
timing chest, where it lubricates the timing chains
and
then drains
to
the sump beneath
the
baffle
plate
at
the bottom
of
the crankcase.
Both pumps are double acting, the primary side
of
the feed
pump
supplying the big ends and
the
secondary side the rockers and valve gear. Both
sides
of
the return pump combine to
pump
oil
back to the
tank
from the sumps
at
the
bottom
of
the crankcase.
A spring loaded relief valve controls
the
pressure
of
the oil to the valve rocker gear which
is
through external pipes.
A gauze strainer
is
provided for thefeed oilleav-
ing the
tank
and
there
is
a large capacityfelt filter in
the feed
to
the big ends. An aluminium cylinder is
fitted over the fixing stud inside the filter element
to reduce the volume
of
oil required
to
fill the
filter after
it
has been dismantled for cleaning
and
to
ensure the rapid
flow
of
oil to the big ends.
A small circular magnet is also fitted over the
fixing stud inside the oil filter for the purpose
of
collecting any ferrous particles which
may
be sus-
pended
in
the oil.
17. Breather
Two separate breathers are fitted
to
ventilate
the crankcase. The driving end
of
the crankshaft
is
drilled through, allowing the engine
to
breath
into the primary chain case which is itself vented
by means
of
a banjo union and a
copper
pipe
running along the top. The second breather
consists
of
drilled passages in the wall
of
the
driving side
of
the crankcase. These communicate
with the breather body situated on the crankcase
wall
just
below the L.H. cylinder base.
From
here
the gases are taken
by
a copper pipe
to
a union
on
top
of
the oil tank and thence
by
another
pipe
to the rear chain. The purpose
of
the connection
to the oil
tank
is twofold. First it allows any
surplus oil carried over to drain back into
the
tank.
Secondly, it provides a vent
to
permit the escape
of
pressure which would otherwise build
up
in
the
tank
due to the difference
in
the capacities
of
the
feed
and
return pumps. Both the. drilled main
shaft
and
the side breather body contain non-
return disc valves which prevent air being drawn
into the crankcase on the up-stroke
of
the pistons
and thus tend to produce a partial vacuum
in
the
c~se. Excessive pressure in the case,
as
shown
by
011
leaks, may be the result
of
one
of
these discs
becoming stuck.
18. Gearbox
The gearbox is bolted
on
to
the
back
of
the
crankcase
and
has four speeds, which are foot
controlled, and a patented neutral finder. All
gears are in constant mesh, changes being effected
by robust dog clutches. (See Subsection 64).
www.hitchcocksmotorcycles.com
Royal Enfield
"Interceptor"
Workshop Manual Page 9
C T
OIL
PUMP
DIAGRAMS T C
Fig. 3A
FEED
PUMP
FEED PUMP
POSIDON
1
POSIDON
2
The
ports
in
the
housing are connected as follows
:-
W delivery
to
rocker gear. Y suction from oil tank.
X delivery
to
big ends. Z - suction from oil tank.
Position 1.
The
plunger A
is
being drawn
out
of
the
cylinder
hole
in
the
disc C by the action
of
the
peg B on the
shaft
D.
The
port
T in the disc C registers with the suction
·
port
Y in
the
housing,
so that oil is drawn
into
the
cylinder
from the oil.
tank.
At
the same time the delivery
port
W in
tht1
housing is uncovered and oil below the disc
in
the housing
is
forced
through
·W
to
the rocker Gear.
I
y
I
z
T' C
RETURN
PUMP
POSmONl
X'
w'
e,/
Fig.JB
Position 2. The plunger A
is
being pushed into the
cylinder hole in the disc
C.
The port T in the disc now
registers with the delivery
port
X in the housing, so that oil
is forced
out
of
the cylinder to the big ends.
At
the same
time the suction
port
Z in the housing is uncovered and oil
is
drawn into the housing below the disc from the oil tank.
y'
I
z.
s'
CT'
RETURN PUMP
POSITION2
;(
W'
The
ports
in
the housing are connected as follows
:-
W'
-delivery
to
oil tank.
Y'
-suction from crankcase.
X'
delivery
to
oil
tank.
Z'
-suction from crankcase.
Position 1.
The
plunger
A'
is being drawn
out
of
the
cylinder
hole
in
the
disc
C'
by the action
of
the peg
B'
on
the shaft
D'.
The
port
T'
in
the disc
C'
registers with the
suction
port
Y'
in
the
housing, so
that
oil
is
drawn into the
cylinder
from
the
crankcase sump.
At
the
same
time the
delivery
port
W'
in
the
housing is uncovered and oil below the
disc in the
housing
is forced through
W'
back to
the
oil tank.
Position 2. The plunger A'
is
being pushed into the
cylinder hole in the disc C'. The port
T'
in the disc now
registers with the delivery
port
X'
in the housing, so that oil
is
forced
out
of
the cylinder back to the oil tank.
At
the
same time the suction
port
Z'
in the housing
is
uncovered
and oil
is
drawn into the housing below the disc from the
crankcase sump.
www.hitchcocksmotorcycles.com
Page
IO
Royal Enfield
"Interceptor"
Workshop Manual
The
standard gear ratios with 20T
and
21T
sprockets are
as
follows:-
20T 21T
Bottom
Gear 12·32 11·75
Second Gear 8·16 7·8
Third
Gear
6·51
5·72
Top
Gear 4·44 4·22
19. Clutch
The
clutch has six pressure plates
and
five
friction plates, including the sprocket which
is
lined
on
both sides with friction material.
On
earlier models this was a moulded material riveted
on
but
later models employ a bonded cork
based
material. The four loose friction plates
on
the
later clutches use the same cork based material
bonded on.
In
earlier clutches the two inside
plates
had
inserts
of
moulded material which
though
it
wo
.uld stand more heat was more liabl~
to slip
if
an excess
of
oil reached the friction
surfaces.
A description
of
the operating mechanism
is
given in Subsection
63.
Service Operations with Engine
1n
Frame
20. Removal
of
the 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. Remove 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 or plugis damaged
a new
one
of
either should be fitted.
The
seal is
Part
No.
42114 and the plug is Part No. 42113.
The
refitting
of
the cover will be facilitated
if
the engineis turned gently forwards while the cover
is
being
put
into place. This will help the engage-
ment
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
slacken the feed plug between the oil pumps.
The
return
oil
pump
can be checked
by
removing
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 circuhting.
The
feed
to
the rockers canbe observed by removing
the rocker-box covers, when oil will be seen
:flowing
down
the surface
of
the push rods.
21. 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 sprocket pointing vertically down-
wards. (See Fig. 4.)
If
it
is necessary
to
remove
the sprockets see Subsections
43
and 44.
Remember
that
all three timing sprocket
fixing bolts have Left-Hand Threads. While
tightening the camshaft bolts the sprockets should
be
held.
The table on page
11
shows the characteristics
of
three al_ternative
c~shaft
and
sprocket arrange-
ments which are available. The choice between
these depends
on
whether
~he
owner wants (1)
good torque and speed with good mechanical
silence or
(2)
maximum torque
up
to
80 m.p.h.
or
(3)
maximum _flat-o~t speed.
When
checking
openmg and closmg pomts do
not
expect precise
agreement with the figures quoted.
The
figures
obtained when checking will depend largely on the
method used to decide when the valve opens
or
closes also,
if
using a dial gauge, whether this is
reading the movement
of
the tappet
or
spring
collar. It must be remembered, too,
that
the
precise timing
of
each valve depends on the
accurate position
of
four keyways and
on
whether
the timing chain is new
or
worn. The figures in
the table are intended as a guide
to
which cams are
fitted and enable a check
to
be made
that
the
timing marks are correctly lined up.
If
opening
and
closing points on the same shaft are early
or
late by about
30°
the sprocket is fitted one
tooth
wrong
22. 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
inlet should be set so
that
the rocker is
just
binding, the exhaust so that
it
is
just
free.
For
www.hitchcocksmotorcycles.com
Royal Enfield
"Interceptor"
Workshop Manual Page
11
APPROXIMATE
TIMING
AT
·012 in.
CLEARANCE
Inlet
Ref.
Camshaft
Sprocket
EX.
opens EX. closes IN. opens
IN.
closes Remarks
B.B.
D.C.
A.T.D.C. B.T.D.C. A.B.D.C.
EX.
32705
l
IN.
32705 36140 82°
(Standard)
EX.
35345
2
IN.
35344 36140 77°
(Sports)
EX. 35345 45207
3
IN.
35344 (Marked
770
(Sports)
"A")
continuous
high
speed work, however, give
the
exhaust
·005 in. clearance. These figures are
for
a
COLD
engine.
To
adjust
the
clearance, loosen
the
locknut
beneath
the
rocker
arm,
turn
the
screw
and
retighten
the
locknut.
The
adjustment
·
of
each valve should be
made
with
the
corresponding valve
in
the
other
cylinder
fully
open.
This
ensures
that
the
tappet
is
on
the
_
neutral
portion
of
the
cam. .
If
the
heads
of
:
the
adjusting screws
are
worn
.-
they
should
be
replaced.
23.
Removal
of
the
Camshafts
Remove
the
timing cover (Subsection 20).
Remove
the
camshaft sprockets (Subsection 44).
Remove
the
three screws holding each
of
the
camshaft
bearing
housings.*
Compress
the
valve springs
and
withdraw
the
camshafts.
It
is necessary to rotate
the
camshafts
slightly while withdrawing them
in
order
that
the
cams will pass
through
the shaped hole
in
the
crankcase. ·
When
replacing the camshafts compress the
valve springs
and
hold
the tappets clear
of
the
cams.
If
the
rocker
adjusting screws are screwed
right
back,
it
is
not
necessary to compress
the
valve
springs.
24. Ignition Timing
To
set
the
ignition tunmg, first
remove
the
timing
cover
(Subsection 20) and
then
remove
the
magneto
sprocket
nut
and
withdraw
the
sprocket,
using Special
Tool
No.
14835 in
the
case
of
the
earlier engines fitted with manual ignition control.
*From
engine
No.
YB16573 onwards
the
fitting
of
detachable
crankshaft
bearing housings was discontinued.
To
remove
the
camshafts
from
these engines
it
is
necessary
to
separate
the
two
halves
of
the crankcase. See Subsections
55, 56
and
57.
35°
35°
35°
Cams have quietening
ramps. Least mech-
35°
82°
anical noise.
Good
torque and speed.
Bettertorque than (1).
37°
60°
Sarne maximum
speed. Noisier.
Torque as (1)
up
to
-
··
80 m.p.h. Better than
22°
75°
(1)
or
(2) above 90
m.p.h.
Noisierthan(l)
When
automatic control
is
fitted no special
extractor is required. Merely unscrew
the
centre
sleeve
nut
which secures
the
auto. advance coupling
to
the magneto
and
keep on unscrewing, when
the
coupling will be
drawn
off its shaft.
Set the
contact
points to ·012/-015 in. when
fully opened.
If
they are worn
or
pitted
a new
set should be fitted. (See Fig. 20, Subsection 80,
for illustration
of
contact breaker.)
Remove
both
sparking plugs
and
set
the
pistons
¼
in.-#
in.
(31
°
to
32°) before
top
dead centre.
Note
which piston is
on
the compression stroke
(both valves closed)
and
which
is
on
the exhaust
stroke (exhaust valve open).
Fit
the magneto chain
and
sprocket, or auto.
advance coupling,
and
tighten the
nut
finger tight.
Set the ignition
control
in the fully advanced
position (manual control) or, in
the
case
of
engines
fitted with automatic advance, rotate the two
halves
of
the
coupling relatively
to
each other
against the springs
and
hold
them
in
this position
with a piece
of
wire.
Now
rotate
the magneto
armature forwards (anti-clockwise looking
at
the
contact breaker) until the points
just
commence
to
open as indicated
by
the fact
that
it
is
just
possible to withdraw a piece
of
thin tissue
paper
from
them.
Tap
the
magneto sprocket
or
auto.
advance coupling
on
to the tapered end
of
the
magneto shaft
and
tighten the centre sleeve nut.
Now
rotate the engine through one revolution
and
check the timing on the other conta_ct breaker
cam. The H.T. pick-up nearest
to
the contact
points when they are in the open position
is
the
"live" one
and
the
H.T.
lead from this must
be
connected
to
the sparking plug
in
the cylinder
which
is
on
the
compression stroke.
Do
not
forget to remove
the
wire holding
the
auto. advance
coupling.
Note.-To
check
the
timing (as opposed
to
resetting it) set
the
pistons
½½
in. before t.d.c.
www.hitchcocksmotorcycles.com
Page
12
Royal Enfield
"Interceptor"
Workshop Manual
with the ignition retarded. Now advance the
timing either by the manual control (when fitted)
or
by
rotating the contact breaker arm anti-
clockwise (auto. advance).
The
points should
just
open in the full advance position.
25. Primary
Chain
Adjustment
The
tension
of
the primarychain can be checked
through the inspection cover in the primary
chain case and, should
it
require adjustment,
access to the adjuster is gained by removing the
chain case cover, which is held in position by a
single
nut
. Before removing
tp.e
nut, place a tray
under
the engine
to
catch
the
oilfrom thechaincase.
Beneath the bottom
run
of
the chain is a curved
slipper on which the chain rests
and
which may be
raised
or
lowered by turning the adjusting screw
after having first slackened the locknut.
A rubber button is fitted
to
the end
of
the
adjustingscrew to prevent the transmission
of
chain
noise
to
the chaincase
and
this is held against the
chaincase by a hairpin spring, which prevents
it
from bouncing.
Do
not
adjust the chain to be dead tight but
rotate
the engine slowly and, while doing so, test
the
tension
of
the
top
run
of
the chain by pressing
it
up
and
down with the fingers. Adjust the
tension so
that
there is t in. up and down move-
ment
at
the tightest spot.
Re-tighten the locknut
on
the adjusting screw,
replace the chain cover
and
replenish with oil
to
the
height
of
the level plug.
26. Timing Chain Adjustment
Before adjusting the tension
of
the timing chain,
turn
the engine until the chain is
in
its tightest
position, checking the chain between all sprockets.
Adjust the tension so
that
there is t in. move-
ment
of
the chain.
The
tension
of
the timing chain is altered by
moving the quadrant after slackening the nut A
which secures
it
(see Fig. 4). This rotates the
eccentric spindle on which the chain tensioner
jockey sprocketis mounted. Tightening
of
the chain
is effected by moving the quadrant to the left.
It
is imperative
that
the quadrant is fitted the
.i:ight
way
round
and
that
the eccentric spindle is
fitted correctly
in
the quadrant fork.
If
the chain
tightens when the quadrant is moved
to
the right,
the tensioner has been wrongly assembled and
may
cause damage
to
the
.quadrant (see Fig.
5).
In
making the adjustment, care must be taken
to see that any backlash in the quadrant is taken
up
in
the
"tightening"
direction, i.
e.
do not make
the
chain too tight
and
then move the quadrant
back slightly,
but
tighten the chain progressively
until
the
correct tension is obtained
and
then lock
the quadrant.
If
the chain becomes too tight
dur
ing adjustment, slacken it right back and make
the adjustment again.
If
the chain is too slack
it
ma,y
give
rise to a
loud noise which can be mistaken for a faulty
bearing.
If
it is too tight the result will be a
high pitched howl.
If
such noises are heard,
therefore, first check the adjustment of the timing
chain.
27. Magneto Chain Adjustment
To adjust the magneto chain tension, remove
the timing cover
(see
Subsection
20)
, slacken the
three magneto
:fixing
nuts, slide the magneto back
until the chain has
about
¼ in. up and down
movement, then tighten
the
fixing nuts.
28. Removal of the Dual Seat
and
Rear
Mudguard
Disconnect the leads
to
the rear lamp by pulling
out the plugs in the connectors near the tool box.
Loosen the two nuts on either side
of
the seat
attaching the mudguard carrier
to
the frame and
lift the seat, mudguard
and
carrier off together.
29. Removal
of
the Petrol
TanJc
The petrol
tank
is
rubber
mounted front and
rear. The front attachment is by means
of
a
_horizontal stud passing through a rubber sleeve
TIMING CHAIN ADJUSTMENT SHOWING TIMING
MARKS
Fig. 4
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Royal Enfield
"Interceptor"
Workshop Manual Page
13
A
CORRECT INCORRECT
TIMING CHAIN ADJUSTMENT
Fig. 5
housed
in
a lug across the frame immediately
behind the steering head.
The
rear fixing
on
the
4¼
gallon
tank
is by means
of
a transverse clamp
and
two bolts which pull the
tank
down
on
to
rubber
blocks above and beneath the
top
tube.
On
the
sm,aller capacity tanks used
in
the U.S.A.
a
rubber
lined
metal clip is used secured
by
two
l in. diameter bolts and nuts. ·
To
remove the tank,
:first
disconnect
the
petrol
pipes,
then
remove the
nut
from one end
of
the
front
attachment
stud
and
knock
out
the stud.
Then
unscrew the nuts or bolts securing the
rear
end
of
the
tank
and lift
it
away, taking care
not
to
damage
the
paintwork on top
at
the
front
end
where
it
may
come into contact with the handlebar
clamp.
It
is preferable
to
remove the
dual
seat
and
rear
mudguard
before attempting
to
lift the
tank.
30. Removal
and
Refitting
of
the Cylinder Head
First
remove the petrol
tank
and
petrol pipe.
(Subsection 29.)
The
dual seat may also be removed
if
desired.
(Subsection 28.)
Remove head steady brackets.
Disconnect the oil pipes and plug leads.
Remove
the
exhaust pipes and carburetter(s),
also
the
induction manifold on single carburetter
models.
Remove the rocker box covers. ·
Turn
the
engine until
both
valves in one head
are closed.
Remove
the
five
cylinder
head
nuts
from
the
head
hit
it
smartly with a hide mallet
beneath
the
exha~st
and
inlet ports (not the fins) and lift
it
off.
Turn
the
engine through one revolution
and
repeat with
the
other head.
When
replacing the heads, see
that
the dowels
are in position
in
the cylinder barrels
and
that the
push rods are the right way up (shallow cups
upwards).
See
that
the taper section "Cross" sealing ring
and its seatings are perfectly clean
and
that the
rubber seals for the push rod tunnels are in good
condition and correctly
:fitted.
With the head
upside down on the bench drop the :packing shim
into the recess first, then the seal with the metal
side downwards. A little jointing compound
should be applied to both sides
of
the "Cross"
sealing ring and the rubber push rod tunnel seals.
Lower
the
cylinder heads over the push rods
making sure
that
the rockers locate
~n
the cups.
Fit the head nuts
and
washers and tighten down
lightly.
At
this stage fit the induction
pi:pe
on
single carburetter models.·
Do
not
overt1ghten
the
nuts-20
lbs. ft. is the recommended figure.
Tighten each
nut
a little at a time in turn. Begin
with the two inside nuts and the one by the spark
plug, leaving the final tightening
of
the corners
to the last.
31. Removal
of
the Valves
Having removed the cylinder head, remove the
rocker-box covers each held by four nuts,
and
swing the rocker cl~ar
of
the valve. Using a suitable
valve spring compressing tool, compress the valve
springs and remove the split collets from the ~nd
of
the valve stem. Slacken back the compressmg
tool and release the springs. Withdraw the valve
and place its springs,
top
spring collar (and
botto~
collar
if
it
is loose)
and
split collets together
Ill
order
that
they may be reassembled with the valve
from which they were removed. .
Deal similarly with the other valves m 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.
REMOVAL OF VALVES
Fig. 6
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Page
14
Royal Enfield
"Interceptor"
Workshop Manual
32. Removal
of
the 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
¼" B.S.F. .
On
reassembling make sure that the sprmg
washers are fitted
on
the sides
of
the rockers
nearest
the
centre
of
the engine and the plain thrust
washers
on
the outer sides.
33. Removal
of
the Valve Guides
To remove the valve guides from the heads two
special tools are r~quired which ~an ea~ily be made.
The
first is a piece
of
tube with an mternal bore
of
not
less than t in.
The second is a mandrel
about
4 in. long made
from ¼ in. diameter
bar
with the end turned down
to
about
fir
in. diameter for ½in. .
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 bead with a
hand
press
qr
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
¼ 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
38
.)
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.
34. Removal
of
the Sparking Plugs
Care
must
be taken when removing
and
replacing
th
e sparking plugs
not
to damage the
threads in the cylinder heads.
If
the threads
do
become damaged, they can
be tapped out
to
a larger size
and
steel wire inserts
fitted.
Special tools are available for tapping
and
inserting the steel wire inserts. The ·latter tool
consists
of
a·piece
of
¼ in. diameter tube
or
rod
with a slot cut in the end.
The insert is placed over the tool with the tag
engaging
in
the slot
and
it
is screwed
i1:1to
the
_Plug
hole
in
the cylinder head from the outside until the
last
coil is 1
to
1½threads below the top face. A
reverse twist
of
the tool will then break off the tag.
If
the cylinder head has been removed, the
fitting
of
the insert will be facilitated
if
the tool is
put
through the hole from the inside
and
the insert
screwed back from the outside.
If
the cylinder head has
not
been removed, 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.
35. Removal
of
the 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
top
dead
centre.
It
is advisable to
put
a clean cloth over the
mouth
of
the crankcase
to
prevent anything, such
as a piece
of
broken piston ring, from falling in.
When replacing the cylinders, clean off the
joint
faces
and
fit
new paper joints, two to each
cylinder.
36. Removal
of
Pistons
Remove the cylinder heads and cylinders.
With a tang
of
a file remove the.two outer
circlips retaining the gudgeon pins. Remove the
long central cylinder studs .which come opposite
the gudgeon pins.
Use Special Tool
No
. E 5477/T to extract the
gudgeon pin or using a
rod
about
tin.
in
diameter
insert this right through one gudgeon
pin
and
drive the other pin
out
of
its piston, supporting
the connecting
rod
substantially meanwhile to
prevent distortion.
Having lifted the first piston away, the other
one may be readily removed
in
the same manner.
Mark
the pistons and gudgeon pins so that they
go back into the same pistons the same way round
and
so that the pistons go back into the same
barrels the same way round.
Take care not to drop the gudgeon pin circlip
into the crankcase. A clean cloth should be put
over the mouths
of
the crankcase
to
prevent this.
37. Decarbonising
Having removed the cylinder heads as described
in Subsection
30,
scrape away all carbon, bearing
in mind that you are dealing with aluminium
which
is
easily damaged. Scrape gently and
avoid scoring the combustion chamber
or
the
valve seats which are
of
austenitic iron ·shrunk
into the head.
Be
careful while performing this
work
not
to injure the
joint
faces which bed down
on to the bead gaskets.
Do
not, in any circumstances, use caustic soda
or
potash for the removal
of
carbon from
aluminium alloy.
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Royal Enfield
"Interceptor"
Workshop Manual Page
15
REMOVAL OF PISTONS
Fig. 7
Scrape away all
carbon
from the valve heads
and
beneath
the heads, being very careful
not
to
cause
any
damage to
the
valve faces.
If
the
piston
rings
are
removed the grooves
should
be cleaned
out
and
new rings fitted.
For
cleaning
the
grooves, a piece
of
discarded ring
thrust
into
a wooden handle
and
filed
to
a chisel
point
is a useful tool. ·
If
the
piston
ring gaps exceed
i\
in. when the
rings
are
in
position
in
the barrel, new rings should
be
fitted.
The
correct gap for new rings
is
·015-·020
in. The gap should
be
measured in
the
least
worn
part
of
the
cylinder, which will be
found
to
be
the
extreme
top
or
bottom
of
the
bore.
While
the
cylinders
and
pistons
are
not
in
position
on
the
engine, cover the crankcase with a
clean
cloth
to
prevent the ingress
of
dust
and
dirt
of
all kinds.
Do
not,
of
course,
attempt
to
scrape
the
carbon
from the pistons when the
mouths
of
the
crankcase
are
open.
38.
Grinding-in
Valves
To
grind a valve, smear the seating with a little
grinding-in compound, place a light, short coil
spring over
the
valve stem
and
beneath the head,
insert the valve
into
its appropriate guide, press
it
on
to the seat using a tool with a suction cup
and
with a backwards
and
forwards rotary motion,
grind
it
on
to
its seat. Alternatively, a tool which
pulls
on
the valve stem
can
be used. Frequently
lift
the
valve
and
move
it
round so that
an
even
and
true seating is obtained.
If
no light spring is
available,
the
lifting will have to be done by hand.
Continue grinding until a bright ring
is
visible
on
both valve
and
seating.
The
faces
and
seats
of
the exhaust valves
are
cut
at
45
degrees
but
the profiles
of
the inlet
valves are
of
a special streamlined design which
eliminates pockets
and
sharp edges and allows a
smooth flow
of
gas without eddies.
If
the inlet valves
or
their seats are pitted
and
require re-cutting, care must be taken to reproduce
the correct profile as shown
in
Fig.
8.
The
cylinder heads should preferably be
returned to
the
Works for the inlet valve seats to
be
re-cut but,
if
this is
not
possible, a special tool
consisting
of
an
arbor
No.
T.2053 and cutter
No.
T.2054 is available.
Great
care must be exercised
in using this
tool
as
it
is located off the valve
guides
and
these
may
be damaged
if
suitable
apparatus is
not
employed.
The
inlet valve faces
and
seats can be cut
at
45
degrees
in
cases
of
emergency but this may
have a deleterious effect
on
the performance
of
the engine.
39. Reassembly after Decarbonising
Before building
up
the engine, see that all parts
are scrupulously clean
and
place them conveniently
to
hand
on
a clean sheet
of
brown paper.
Check the
piston
ring gaps to find out whether
excessive wear has
taken
place (see Subsection 37).
It
is advisable to fit new gaskets to the cylinder
base
and
cylinder head.' Two paper gaskets are
fitted to the base
of
each cylinder.
Smear clean oil over the pistons, having
replaced the rings
if
these have been removed,
lower the piston over the connecting
rod
and
insert
the gudgeon pin from the outer side. Fit the
circlip
and
then
fit
the
second piston in a similar
manner.
Oil the cylinder bores
and
lower the barrels
over the pistons
and
seat them gently on their
gaskets. ·
Drop
the
push
rods down their tunnels on to
the
tappet
heads, shallow cups upwards.
Replace
the
cylinder heads as described in
Subsection 30.
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Page
16
Royal En.field
"Interceptor"
Workshop Manual
s·
le.
DIA.
IN
LE.T
VAL-Va:
INLET VALVE SEAT PROFll,E
Fig. 8
After
the engine has been assembled,
run
it
for a
brief
period
at a speed which will ensure
that
t~e
ignition has been advanced by the automatic
advance device.
Ifit
is
run
too slowly
"blueing"
of
the
exhaust pipes may take place.
After the engine has been run for some time
and
has become thoroughly hot,
go
over
all
the
cylinder head
and
other nuts
to
ensure that they
are
tight.
40. Cleaning
the
Oil Filters
The
oil filter is located
in
the timing cover
immediately below the oil pumps
and
is in the
feed circuit
to
the big ends.
The
filter element is removed by unscrewing
the
nut
holding the end cap in position. When
reassembling
the
filter after cleaning, take care
that
no
grit
or
other foreign matter
is
sticking_
to_
it.
The
.aluminium.cylinder fitted over .the rod
ms~de
the
filter element is
to
reduce the free space which
has
to
be
filled after cleaning before oil reaches
the
big ends. After
empt~g
the filter chamber
it
is essential
to
run the engme slowly for about
five minutes
to
ensure that oil
is
reaching the big
ends.
Thefelt element should be taken out
and
washed
in petrol after the first 500 miles and after every
subsequent 2,000 miles.
Fit
a new element
every 5,000 miles.
41. Overhaul
of
Oil Pumps
Remove the timing cover as described in
Subsection
20
.
Remove the end plates from both pumps.
Remove the pump discs and plungers.
Remove the pump spindle which can be pulled
out
from the front or return
pump
end
after
removal
of
the lQcating screw.
Check the fit
of
the plungers in the pump discs
which should have a minimum
of
clearance
but
should be able
to
be moved in
and
out by hand.
If, when fitting a new disc or plunger,
the
plunger is found
to
be too tight a fit, carefully
lap
with metal polish until it is
just
free.
If
the
pump
disc is
not
seating properly
or
if
a new pump disc
is being fitted, it should be lapped to the seating
with Special Tool No. E.5425, using Carborundum
360 Fine Paste
or
liquid metal polish until
an
even grey surface is obtained. .
Wash all passages, etc., thoroughly with petrol
after lapping to remove all traces
of
grinding paste.
. Check the pump disc springs for fatigue by
assembling
in
the timing cover
and
placing
the
pump
covers in position.
If
the
springs are correct,
the pump cover should be held ¼in. off the timing
cover by the
pump
spring.
Thepump spindle should be renewed
if
excessive
wear has taken place on the teeth.
Reassemble the oil pumps, replacing
the
paper cover gaskets
if
necessary. Before fitting
each cover
fill
the pump chamber with clean oil.
Having assembled the pumps, lay the timing
cover flat
and
fill
the oil ports
by
means
of
an
oilcan.
Tum
the pump spindle with a screw
driver in a clockwise direction looking on
the
front
and
it
can then be seen whether the pumps
are
operating correctly.
CORRECT RELATIVE POSITIONS OF DUAL
SCRAPER RINGS
Fig. 9
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Royal Enfield
"Interceptor"
Workshop Manual Page
17
Fill
the
filter chamber with clean oil and replace
the
timing
cover, taking great care
not
to damage
the
gasket
where the section is narrow. (See
Subsection
20.)
When
the
timing cover bas been refitted
on
the
engine,
the
oil feed to the big ends
can
be checked
by
partially
unscrewing the feed plug in the timing
cover
between
the oil pumps. The oil
return
to
the
tank
can
be
checked by removing the oil filler
cap.
The
feed to the rockers
can
be observed
by
removing
the rocker-box covers, when oil will
be seen flowing down the surface
of
the push rods.
42. RemovaJ
of
the
Timing Chains
Remove
the
magneto
and
chain (Subsection
45). ·.
Loosen
the
chain tensioner locknut
and
stud.
Lift
the
adjusting plate clear
of
the chain
tensioner spindle.
Remove
the
chain tensioner spindle
and
sprocket.
Lift
the
chain off the sprockets.
43. Removal
of
Pump
Worm
and
Timing Sprocket
Remove
the
timing chains (Subsection 42).
Unscrew
the
oil .pump worm by means
of
the
.
hexagon
head
behind it. This is a Left-Hand
Thread.
Withdraw
the timing sprocket using Special
Tool
No.
E.4869.
44. Removal
of
the
Camshaft Sprockets
Remove
the
timing chains (Subsection 42).
Unscrew
the camshaft sprocket fixing bolt,
which has a Left-Hand Thread,
at
the same time
holding
the
sprocket.
Withdraw
the
sprocket
by
means
of
a suitable
extractor.
45. Remova1
of
the
Magneto
Remove
the timing cover (Subsection 20).
Remove
the magneto sprocket or auto-advance
coupling (Subsection 24).
Remove
three fixing nuts and withdraw the
magneto.
46. Removal
of
the Engine
and
Clutch Sprockets
The
primary
chain is endless so that
it
is
necessary
to
remove
both
the engine and clutch
sprockets simultaneously.
The
alternator
stator is removed by undoing
the
three
fixing nuts, after which the stator
can
be
pulled
off
the
three studs on which
it
is located.
Remove
the
central hexagon bolt securing the
alternator
rotor,
which can then be drawn off,
taking
care
not
to
lose the key.
Unscrew the engine sprocket nut, using Special
Tool No. E.4877. The engine sprocket
is
mounted
on splines and can then be removed with the clutch
sprocket.
To 'remove the clutch sprocket, unscrew the
three pressure plate pins and remove the pressure
plate assembly, the centre retaining plate and the
assembly
of
driving
and
driven clutch plates. The
clµtch sprocket can then be withdrawn from the
centre after the removal
of
the large circlip which
secures it.
47
~
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
30
and
35.)
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 inwith a bronze drift, care being takenwhen
the guide
is
nearly home to avoid breaking the
collar.
If
a tappet ·guide is taken out it should be
replaced by
an
oversize one.
48. 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. .
The breather which operates through the
crankshaft,
may
be inspected by removing the
slotted plug
from
the
head
of
the rotor retaining
bolt. (See Fig. 10.)
49. Removal of the Clutch
Remove the engine sprocket
and
clutch sprocket
together as described in Subsection
46.
To remove the clutch hub; hold the clutch with
www.hitchcocksmotorcycles.com
Page
18
Royal Enfield
"Interceptor"
Workshop Manual
CRANKCASE
BREATHER
·····•
··
-
--
•-•
«
--
---
---
-·- --
---
----
--
- --·--.
..
CRANKCASE
BREATHERS
Fig.10
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.
50. Removal of the Final Drive Sprocket
Remove the clutch as described in Subsection
49. Remove the primary chain tensioner.
Remove the rear
half
of
the primary chain
case
by
taking out three socket screws and the
centre
stud
. ·
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 with-
drawn.
51.
Oil Seal Behind Engine Sprocket
This consists
of
a neoprene oil seal, with a
garter
spring, backed
up
by
either one
or
two steel
washers. The correct order
of
assembly is as
follows:-
(!)
Press the oil seal W43382 into the chain
case ·
from
the front with the ·garter spring facing
the
inside
of
the case. The seal should be pressed
in
till its outer face is flush with the inner surface
of
its housing
in
the
back
half
of
the chain case.
(2)
Into
the
recess thus formed
at
the back
of
the
chaincase fit the thicker washer W34069.
(3)
If
provided, fit
the
thinner washer W34068
so
that
it
lies between W34069 and the edge
of
the
outer race
of
the driving side main ball bearing.
(4)
Fit
the back
half
of
the
. chain case to
the
engine
and
tighten the three socket screws W38027.
This should result
in
the oil seal being pushed
in
1 to the chain case so
that
its face stands slightly
·
proud
of
the inner surface
of
its housing.
(5)
Fit
the engine sprocket, taking great
care
'
not
to damage the lip
of
the seal when pushing
the
sprocket through it.
52. Oil Pipe Unions
The oil feed to the rocker gear is through pipes
' from unions
at
the back
of
the crankcase below
1 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 aluminium
from
stripping.
The method
of
fitting
the
thread inserts is
the
same as
that
used for the sparking plug inserts
described
in
Subsection
34.
53.. Rocker Oil Feed Relief Valve
There is a pressure relief valve
in
the oil supply
to the rocker gear, whose function is to prevent
excessive pressure
and
whose setting is
not
critical.
The valve is located
in
the crankcase face
behind the timing cover
and
consists
of
a ¼
in
.
diameter steel ball held in position by a spring and
a brass plug.
The valve is set before leaving the Works and
should
not
normally require
to
be disturbed but,
if
it
is found necessary
to
dismantle it,
it
can be
reset by screwing the plug
in
until it is flush with
the face
of
the crankcase, which will cause the
pressure
to
be relieved
at
approximately
10
lbs.
per
square inch. The plug is prevented from moving
by peening over the aluminium into the screw-
driver slot with a small centre punch.
54. Fitting the Alternator
The
alternator consists
of
two parts, the stator
anti the rotor.
The
stator
is
mounted
on
to the primary chain-
case with three studs and distance pieces.
The
rotor
, which contains the permanent
magnets, is mounted
on
the
end
of
the crankshaft
and
is located by a key
and
secured by a special
bolt
and
washer.
The radial air gap between the rotor
and
the
poles
of
the stator should be ·020 in.
in
all positions
and
care must be taken when refitting to see that
it
is
not
less
than
·010 in.
at
any point.
Fit
the
rotor
first, making sure
that
it is located
concentrically
on
the end
of
.the crankshaft.
Attention must be given
to
the seating
of
the
key
www.hitchcocksmotorcycles.com
Royal Enfield
"Interceptor"
Workshop Manual Page
19
because
a badly-fitting key may cause
the
rotor
to
run
unevenly. Finally secure the
rotor
with the
appropriate
bolt
and washer.
Place
the
three distance pieces over the three
chaincase
studs. The stator can
then
be fitted,
with
the
coil connections facing outwards.
Replace
the
nuts
and
shakeproof washers only
finger-tight,
and
insert six strips (preferably
of
non-magnetic
material) ·015 in. thick
and
about
¼in. wide between the rotor
and
each pole piece.
Tighten
the stator nuts
and
withdraw
the
strips.
Check
the
air gap with narrow feelers and,
if
less
than
·010 in. at any point, remove the stator
and
set the three studs carefully until the correct
gap is obtained.
An
alternative, and more satisfactory, method
of
assembling the 'alternator requires
the
use
of
Special Tool No. T2055/19.
This is a gauge ·015 in. greater
in
radius than
the
rotor
and
fits over the
adaptor
on
the end
of
the crankshaft
in
the rotor's place.
The
stator
is then
put
in position
on
the studs
in
the chaincase
and
the nuts tightened up.
Remove the gauge
and
fit
the
rotor, then check
the air gap.
Service Operations with Engine Removed
55. Removal
of
the
Engine
Gearbox Unit
from
the Frame
Disconnect
the battery leads.
Remove
the
dual seat
and
petrol tank.
Remove
the
engine steady.
Remove
the
tool box cover
and
slide the
flexible connection to the air cleaner off the
, ,".induction·
pipe
(where fitted).
Remove
the
exhaust pipes.
Disconnect
the electric
horn
leads.
•
Loosen
the
rectifier bracket
and
swing ·the
rectifier clear.
Remove
contact breaker cover.
Remove
carburetter fixing pins.
Remove
the
rear chain.
Disconnect
the clutch cable.
Remove
the
footrest bar.
Remove
the
bottom
rear engine
bolt
and
the
bolt
securing
the gearbox bracket
to
the
frame.
Loosen
the
nuts on the chainstay
pivot
bolt.
Support
the
engine
on
a suitable box
or
wood
block. . .
Raise
the
centre stand
and
remove
the
spring.
Loosen
the
bottom gearbox nuts
and
swing the
lower engine plates down.
Remove
the
front engine plates,
horn
and
stand.
Lift
the
engine out
of
the frame.
56. Removal
of
the
Gearbox
Remove
the
engine sprocket
and
clutch (Sub-
sections 46
and
49).
Remove
the rear
half
of
the primary chaincase
by
removing
three socket screws
and
the
centre
stud. .
The
gearbox
and
gearbox bracket
can
now
be
withdrawn
from
the back
of
the crankcase after
unscrewing
the
four nuts which secure them,
57. Dismantling
the
Crankcase
Drain
the oil
tank
by removing the drain plug.
Having removed the engine from the frame as
described in Subsection
55,
dismantle
the
.heads,
barrels, pistons, timing gear
and
magneto, as
described
in
Subsections 20, 30, 35, 36, 42, 43, 44
and
45.
Remove the gearbox as described
in
Subsection
56.
Remove the two hexagon-headed plugs on the
driving side
of
the crankcase
just
below the cylinder
base.
Access can
now
be obtained through the plug
holes
to
two screws holding the two halves
of
the
crankcase together which must
be
removed. (See
Fig. 11.)
Remove three nuts
in
the timing chest, two
nuts
on
the driving side crankcase, two loose studs
through the
bottom
of
the crankcase
and
two loose
studs through the back
of
the oil tank. (The other
studs have already been removed to take the engine
out
of
the frame.)
Turn
the crankshaft until the connecting rods
are
at
bottom
dead centre
and
the two halves
of
the
crankcase can then be separated, tapping the
crankcase with a soft mallet.
The inner race
of
the roller bearings on the
timing side will remain
on
the crankshaft bringing
with
it
the cage
and
rollers
and
leaving the outer
race fixed to the crankcase.
The inner race
of
the ball bearing
on
the driving
side
is
a tight fit
on
the shaft
and
can be removed
with Special Tool No. E.5121.
If
this is
not
avail-
able, the shaft can be driven
out
with a hide mallet
or
a soft metal drift.
To
avoid damage to the ball bearing the case
should
be
heated
to
about
100°C. before doing this.
www.hitchcocksmotorcycles.com
Page
20
Royal Enfield
"Interceptor"
Workshop Manual
,,,,
,,
,
.
.
0
............
.
~
~
/d''I
B
REMOVAL
OF
SCREWS
IN
CRANKCASE
Fig.11
58. Main Bearings
To
remove the ball bearing from the driving
side crankcase, heat the crankcase
to
about
100
degrees C. by immersion in
hot
water or in an
oven after which the bearing
can
be driven out
using a drift
which
applies pressure to the outside
race only.
When
refitting a new ball bearing, heat the
crankcase
in
the same way
and
use the same drift
taking great care to keep the bearing square with
the bore.
To
remove the outer roller race from the timing
side crankcase, first heat the crankcase then drive
the race
out
using a small punch
through
the three
holes provided.
The
inner race
and
rollers
can
be withdrawn
from the crankshaft using a claw type extractor.
When
refitting the inner race drive
it
on to the
shaft until just flush with the end
and
no further.
59. Fitting
the
Connecting Rods
To
remove the connecting rods from the crank-
shaft, unscrew the socket screws
in
the connecting
rods,havingfirst removed thesecuritywires through
the heads
(if
fitted).
If
the big end bearings caps are removed
to
examine the condition
of
the bearings, make sure
that the caps are refitted the same way round on
the same rods and that the rods themselves are
refitted the same
way
round
on
the same crank pins.
In refitting the connecting rods, the socket
screws should be tightened with a torque wrench
set
at
250 in. lb.
(21
ft. lb.).
No
cotter pins
or
other locking devices are
fitted.
If
the socket screws
a:re
correctly tightened
they will never come loose.
If
they are not ade-
quately tightened they are liable
to
fatigue failures.
Use only genuine big end screws, Part No.
47876
These have a very high fatigue strength due to the
use
of
a special steel and the fact that the threads
are rolled after heat treatment. Wiring the heads
is
not
recommended.
If
it is necessary to replace the big ends, a
service crankshaft can be supplied with connecting
rods fitted.
60. Reassembly
of
Crankcase
If
the main bearings have been removed fit
the replacement ball bearing in the driving side
crankcase
and
the
outer roller race
in
the timing
side
as
described
in
Subsection
58.
The outer
race should be pressed home until
it
nips the steel
and rubber oilsealW46200 (steel washer W36275/A
on early engines)
and
should then be secured
1:>y
making four equally spaced centre punch marks
in the case so as to spread the aluminium over the
radiused edge
of
the race.
Assembly
of
the two halves
of
the crankcase
on to the crankshaft is easier
if
the crankcase
is
warmed while the crankshaft
is
cold.
If
the driving
side
is
fitted first take particular care
not
to
knock
a roller out
of
the timing side main bearing when
fitting the timing side
case-this
could cause
serious damage
to
the engine. Risk
of
this
is
obviated by fitting the timing side
of
the case first
but,
if
this
is
done, care must be taken not to
rotate the crankshaft until
it
has been located end-
ways by fitting the engine sprocket and tightening
the
nut
right home. Rotation
of
the shaft before
it
is
positioned correctly could score the inside
of
the timing side
of
the case.
It
is
possible to assemble the crankcase cold
but the bearing clearances will
then
be reduced.
This may necessitate wrapping a piece
of
thin
string round the rollers
of
the timing side bearing
to ensure their easy entry into the outer race.
When cold it will be necessary to draw the.driving
end
of
the crankshaft through the ball bearing by
means
of
the sprocket
nut
and
a temporary distance
piece used in place
of
the sprocket and somewhat
shorter than it.
The
nut
and
distance piece must
then be removed and the shaft locked into place
by
tightening the
nut
after fitting the sprocket.
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