A.J.S. 16 User manual

INSTRUCTION BOOK
A
•
A• A
J
•
S
350
c.c.
Model
16
500
c.c.
Model
18
SINGLE CYLINDER
MODEL
SPINGTWINS
Standard 20 and 20 De-Luxe (500 c.c.)
Standard 31 and 31 De-Luxe (650 c.c.)
CS and CSR Models (650 c.c)
Issued by:
A.J.S. MOTOR CYCLES : LONDON S.E.18
Proprietors : ASSOCIATED MOTOR 'CYCLES LTD.

INSTRUCTION BOOK
Factories:
BURRAGE GROVE and MAXEY ROAD
PLUMSTEAD, S.E.18
Telephone: WOOIwich 1223 (7 lines)
Telegrams: "ICANHOPIT, WOL-LONDON"
Cables: "ICANHOPIT, LONDON" TELEX 22617
Codes: A.B.C. 5th and 6th Edition; Bentley's; and Private Codes
Registered Offices:
PLUMSTEAD ROAD, PLUMSTEAD
LONDON S.E.18 ENGLAND
Issued by:
A.J.S. MOTOR CYCLES : LONDON S.E.18
Proprietors: ASSOCIATED MOTOR CYCLES LTD.
A•J•S
350 c.c. SINGLE CYLINDER MODELS 500 c.c.
500 c.c. TWIN CYLINDER MODELS 650 c.c.

Carburetter
Controls
Data
Driving
Electrical Equipment
Engine
Forks and Frame
Free Service
Guarantee
Index
Information
Lubrication
Maintenance
Repairs and Service
Spare Parts
Tools and Special Equipment
Transmission
Wheels and Brakes
44
7
4
9
73
26
56
94
98
99
88
12
24
91
95
96
47
63
CONTENTS
PAGE
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2

HE MODERN MOTOR CYCLE unquestionably provides one of the
most healthy, economical and pleasant means of transport. In
addition, by reason of its superb braking, high power to weight ratio and
ease of control it is, if used with due care, one of the safest vehicles on
the road.
It is our sincere desire that every owner should obtain from his mount
the service, comfort and innumerable miles of low cost travel that we have
earnestly endeavoured to build into it.
It must be borne in mind, however, that although of simple design and
construction, it is nevertheless a highly specialised piece of engineering
and must in consequence be intelligently and efficiently maintained in
order to provide unfailing reliability.
In this book we provide non-technical instructions for carrying out all the
maintenance operations likely to be called for in normal service, together
with assisting illustrations.
To owners of long experience we tender apologies for the elementary
nature of some of the contents of this handbook, but owners, whether
novice or expert, are advised to read the contents from beginning to end.
We are at all times pleased to give owners the full benefit of our wide
experience in matters relating to motor cycles of our manufacture and
elsewhere will be found details of the particulars required when making
enquiries of our Service Department.
N the interest of Safety on the Road, a few words of warning will not
be out of place.
The outstanding* manoeuvrability of a motor cycle over most other
vehicles on the road makes it necessary to exercise caution at all times.
There are, unfortunately, a few motor-cyclists whose reckless driving
constitutes a menace not only to themselves but also to other road users
resulting in the totally false impression in some quarters that motor-
cycling is a dangerous pastime.
REMEMBER IT IS NOT THE MOTOR CYCLE THAT CAUSES
ACCIDENTS, IT IS THE MAN WHO IS RIDING IT.
Take a pride in your riding technique and never rely upon the other
fellow doing the right thing.
Your example of careful and courteous riding will materially contribute
to road safety and to the reputation of a fine sporting pastime.
NO ACCIDENTS PLEASE
Your motor cycle, as issued from the factory, is fitted with an efficient
silencing system, and with careful and unobtrusive driving, particularly
in built-up areas, will not cause annoyance to the general public.
Owners who interfere with the silencing system by removing the baffles
are purely exhibitionists and such conduct can only bring motor-cyclists
in general into disrepute.
Safety on the Road
T
I
3

Identity—Singles
Engine Number Stamped on left-hand side of crankcase
Frame Number Stamped on main frame head lug
Identity—Twins
Engine Number Stamped on crankcase left in front of cylinder
Frame Number Stamped on main frame head lug
Engine Capacities
350 c.c. Single
500 c.c. Single
500 c.c. Twin
650 c.c. Twin
Bore 69 mm.
Bore 82·5 mm.
Bore 66 mm.
Bore 72 mm.
Stroke 93 mm. =347 c.c.
Stroke 93 mm. =498 c.c.
Stroke 72·8 mm. =498 c.c.
Stroke 79·35 mm. = 646 c.c.
Cylinder Sizes
Cylinder bore size —350 c.c. elgniS s 2·7187 ins.
Cylinder bore size —500 c.c. elgniS s 3·250 ins.
Cylinder bore size —500 c.c. iwT n 2·598 ins.
Cylinder bore size —650 c.c. iwT n 2·8345 ins.
(All measurements subject to a tolerance of + or — ·0005 ins.)
Carburetter—Singles
Main jet
Main jet (air filter fitted)
Pilot jet
Throttle valve
Choice size
Needle position
Needle jet
350 c.c.
376/100 size 210
200
376/076 size 30
376/060 size 3½
1·z in.
Central notch
376/072 size ·1065
500 c.c.
376/100 size 260
250
376/076 size 30
389/060 size 3½
1·E in.
Central notch
376/072 size ·1065
Carburetter. (Standard, De-Luxe and Sports Twins)
Main jet
Mainjetairfilter
Pilot jet
Throttle valve
Needle position
Needle jet
Choke size
500 c.c.
220
210
25
4
Centre
·1065
1 in.
650 c.c.
390
340
20
4
4
·1065
18in.
650 c.c. Sports
450
390
20
4
4
·1065
18in.
Capacities—All
Location
Gear box
Front fork (each side)
Rear wheel fork hinge bearing
Fuel tank
Oil tank (to top level mark)
Front chain case—Singles
Front chain case—Twins
British
1 pint
6½ fl. ozs.
1½ fl. ozs.
3¾gallons
4 pints
12 ozs.
8 ozs.
Metric
568·2 c.c.
184·6 c.c.
42·6 c.c.
17·04 litres
2·5 litres
340 c.c.
230 c.c.
Compression ratios—Singles
Model
350
500
Normal ratio
7·5 to 1
7·3 to 1
Low ratio
According to piston.
See Spares List for
ratios available.
Compression ratios—Twins (Standard and De-Luxe models), CS and CSR model
With standard pistons
With alternative pistons
500 c.c.
8 to
1
7 to 1
650 c.c.
7·5 to 1
6·75 to 1
CS and CSR Model
8·5 to 1
7·5 to 1
Make
Lucas
Type
MA6
Point gap
·014—·016 in.
Ignition coil
DATA
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4

Ignition (Magneto)—Twins
Make
Lucas
Type
K2F
Rotation
Anti-clock
Point gap
·012 in.
Model
Std.
CSR model
Make
K.L.G.
K.L.G.
Type
FE80
FE220
Thread
14
mm.
14 mm.
Reach
¾in.
¾in.
Point gap
·020 to ·022 in.
·020to ·022 in.
Crankpin
H—1·62575 in.
L—1·62525 in.
Centre bearing
H—1·62675 in.
L—1·62625 in.
Sparking Plug
Connecting rod—Twins
Internal diameter small end oegduG n pin diameter
¾ in. + ·0005 in (H) ¾in. – ·0001 to – ·0003 in.
¾ in. – ·0000 in. (L)
NOTE—The 650 c.c. con rods use chamfered end caps. Early type rods will not interchange.
Crankshaft diameters
Pistons (standard size). Top skirt diameter (Twins)
500 c.c.
H—2·5933 in.
L—2·5925 in.
650 c.c.
H—2·8295 in.
L—2·8287 in.
Pistons (standard size). Top skirt diameter (Singles)
350 c.c.
2·7176 in.
+ or – ·0005 in.
500 c.c.
3·2437 in.
+ or – ·0005 in.
Piston rings
Normal gap ·006 in. maximum permissible ·030 in.
Engine shaft location—Singles
If the flywheel driving side shaft is removed it must be correctly located otherwise the efficiency of the
alternator will be impaired.
On the face of the driving side flywheel is a mark in the form of a "dot". The key for the rotor must
line up with this marking, for correct location.
Valve guide projection (top of guide to boss)—Singles
Inlet—½ in. Exhause—½ in.
Valve timing pinion-—Singles
Retained by nut, threaded vin. by 26 threads per in. Left hand thread. Part number 000221.
Valve springs—Singles
Free length (between centre of wire)— 2 in.
Renew when xto ¼ in. less than normal free length.
Valve springs—Twins
Outer valve spring gnirpsevlavrInne
Free length Part number Free length Part number
2 33/64 in. 018348 2Q in. 018347
Renew valve springs when 3/16 to 1/4 in. less than normal free length.
Valve timing
All timing gears are marked for ease of setting. See page 34 and 42.
Oversize parts—Singles
The following are the only "oversize" variations provided for the 350 and 500 c.c. Single Cylinder machines
Big-end rollers: Cylinder re-bore: Pistons and rings:
·001 in. oversize ·020 in. and ·040 in. oversize ·020 in. and ·040 in. oversize
Oversize or undersize parts—Twins
The following are the only "oversize" variations provided for the Vertical Twin machines.
Big-end and crankshaft centre main bearings:
Undersize
Cylinder re-bore:
·020 in. and ·040 in. oversize
·010 below normal. (Journals to be re-ground to suit)
·020
·030
Pistons and rings:
·020 in. and ·040 in. oversize
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5

Camshaft gears
Retained by nut. Left hand thread.
Weight
Weight of machine with empty tanks:
350 Single Model
500 Single Model
500 Twin Model
650 Twin Model
382 lbs.
394 lbs.
398 lbs.
405 lbs.
Gear ratios—Singles
Engine Sprocket size
16 teeth
17 teeth
18 teeth
(a) 19 teeth
(c) 20 teeth
21 teeth
(b) 22 teeth
First gear
17·63 to 1
16·6 to 1
15·65 to 1
14·85 to 1
14·11 to 1
13·42 to 1
12·81 to 1
Second gear
11·7 to 1
11·05 to
1
10·39 to 1
9·86 to 1
9·37 to 1
8·93 to 1
8·52 to 1
Third gear
8·41 to 1
7·91 to 1
7·46 to 1
7·07 to 1
6·73 to 1
6·41 to 1
6·11 to 1
Fourth gear
(top)
6·89 to 1
6·48 to 1
6·12 to 1
5·80 to 1
5·51 to 1
5·25 to 1
5·01 to 1
(a) Standard for 350 c.c. Touring Models. (b) Standard for 500 c.c. Touring Models.
(c) S/C Engine Sprocket.
Gear ratios—Twins
Engine sprocket size
(c) 19 teeth
20 teeth
(a) 21 teeth
22 teeth
(b) 23 teeth
First gear
14·85
14·11
13·42
12·81
12·23
Second gear
9·86
9·37
8·93
8·52
8·15
Third gear
7·07
6·73
6·41
6·11
5·85
Fourth gear
(top)
5·80
5·51
5·25
5·01
4·79
(a) Standard 500 c.c. Engine Sprocket.
(c) S/C Engine Sprocket 500 c.c. (b) Standard 650 c.c. Engine Sprocket. (a) S/C Engine Sprocket 650 c.c.
Sprockets
Location
Clutch
Gear box
Rear wheel
Number of teeth
42
16
42
Gear box ratios (internal)
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First gear
2·56 to 1
Second gear
1·70 to 1
Third gear
1·22 to
1
Fourth gear (top)
1 to 1
Chain sizes
Front (all Models)
Rear (all Models) ½ in. by ·305 in.
ain. by sin.
Chain length
Front—350 Single 67 links
500 Single 69 links
500 Twin 67 links
650 Twin 68 links
Rear—350 Single
500 Single
All Twins
98 links
98 links
97 links
Wheels (bearing end play)
Bearing end play ·002 ni . (just perceptible rim rock)
6

(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
(13)
(14)
(15)
(16)
(17)
(18)
(19)
(20)
Throttle twist grip. On right handlebar. Twist inwards to open. When
fully closed engine should just idle when hot.
Air lever. Small lever on right handlebar. Pull inwards to increase air supply
to carburetter. Once set, when engine has warmed up, requires no alteration
for different road speeds. Should be fully closed when starting engine from cold.
Ignition lever. Small lever on left handlebar. Advances and retards ignition
point. Pull inwards to retard. Retard two-fifths of total movement for starting.
Magneto cut-out switch. Push switch on magneto contact breaker cover. A
press action switch which, when operated, short circuits the magneto, thereby
stopping the engine from firing. Place gear foot lever in neutral position before
using cut-out switch to stop engine.
Clutch lever. Large lever on left handlebar. Grip to release clutch so that
drive to rear wheel is disconnected.
Front brake lever. Large lever on right handlebar. Grip to operate front
wheel brake and, for normal braking, use in conjunction with rear brake application.
Rear brake lever. Pedal close to left side foot rest. Depress with left foot to
apply rear brake. Apply gently and use increasing pressure as the road speed
decreases.
Gear change lever. Pedal in horizontal position close to right foot rest. Con-
trols selection of the four speeds, or ratios, between engine and rear wheel
revolutions, with a "free", or neutral, position. See illustration 2, page 10.
Kick-starter lever. Vertical pedal on right hand side of gear box.
Lighting switch. In top of head lamp. Controls lamps by a rotating lever which
has three positions:
(1) "OFF" Lamps not on.
(2) "L" Pilot lamps, rear lamp and speedometer lamp on.
(3) "H " Main headlamp, rear lamp and speedometer lamp on.
Ammeter. In top of head lamp. Indicates flow of electric current, in, or out,
of battery. ("Charge" or "Discharge".)
Horn switch. Press switch on left handlebar.
Gear box filler cap. Located on top edge of kick-starter case cover. Allows
insertion of lubricant and access to clutch inner wire and internal clutch operating
lever.
Footrest for rider.
Petrol tank filler cap. Located in top of fuel tank. To release, slightly depress,
turn fully to the left, and then lift away. There are two locking positions. The
middle position, between the fully tightened down and "lift away" positions, is in
the nature of a "safety" device to prevent loss that might be occasioned by
unauthorised meddling.
Oil tank filler cap. Located on top edge of oil tank. To remove, unscrew.
Dipping switch. Trigger switch on left handlebar. Used to select normal or
"dipped" beam of head lamp when main lighting switch lever is in the " H " position.
(The main head lamp bulb has two filaments.)
Dummy grip. The fixed grip on the left handlebar.
Speedometer hand. The rotating hand in speedometer head. Indicates speed
in miles per hour to a maximum of 120 miles per hour. (Certain machines for
export have the head calibrated in kilometres per hour to a maximum of 180 k.p.h.)
Total mileage recorder. The top set of figures located in the speedometer dial.
Indicates the number of miles (or kilometres) travelled to a total of 100,000 and
then automatically re-sets to zero. -
Refer to Illustration 1
CONTROLS
7

(21)
(22)
(23)
(24)
(25)
(26)
(27)
Trip mileage recorder. The bottom set of figures located in the speedometer
dial indicates the number of miles (or kilometres) travelled since the recorder
was set to zero. Can be re-set at any time. Used to measure the length of
individual trips. The red figures indicate tenths of a mile. Unless re-set, indicates
a total of 1,000 miles and then automatically re-sets to zero.
Re-set knob. Protrudes from lower part of speedometer head. Pull and turn
to right till "000·0" appears to re-set the trip mileage recorder.
Gear indicator. Moves under the control of the gear change lever and the
number registering with a line on gear box indicates gear in engagement (or
neutral).
Pillion foot rest. Fold upwards to a vertical position when not in use.
Fork top bolt. One at top of each fork main inner tube. Must be raised to
allow insertion of hydraulic fluid.
Ignition switch. (See page 73.)
Valve lifter. Small lever on left handlebar.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
THROTTLE TWIST GRIP.
AIR CONTROL.
IGNITION CONTROL.
MAGNETO CUT OUT (on
Magneto Contact-Breaker
Cover) (Twin).
CLUTCH LEVER.
FRONT BRAKE LEVER.
REAR BRAKE PEDAL.
GEAR CHANGE LEVER.
KICK-STARTER PEDAL.
LAMP CONTROL SWITCH.
AMMETER.
HORN BUTTON.
GEAR BOX FILLER CAP.
RIDER'S FOOTREST.
PETROL TANK FILLER CAP.
OIL TANK FILLER CAP.
HEADLAMP DIP SWITCH.
DUMMY GRIP
SPEEDOMETER, MILES PER
HOUR DIAL.
SPEEDOMETER, TOTAL
MILEAGE.
SPEEDOMETER, TRIP
MILEAGE.
SPEEDOMETER, TRIP
RECORDER RESET KNOB.
GEAR POSITION
INDICATOR.
PILLION FOOTRESTS.
FORK TOP BOLT (Remove
to add oil).
IGNITION SWITCH.
VALVE LIFTER.
Illustration 1
Controls
Before using the machine, sit on the saddle and become familiar with the position and
operation of the various controls. Pay particular attention to the gear positions.
If any adjustment is made to the rear brake pedal make certain the brake does not bind
and also see there is not excessive free pedal movement before the brake comes "on".
8

FUEL
Although various quality fuels are again available owners are advised to use only the
best. The small economy that might be considered to accrue by using the cheaper
grades is more than offset by the advantages obtained by using only Premium Grades.
FUEL SUPPLY
Two fuel feed taps are situated underneath the rear end of the petrol tank. (One each
side.) Both must be shut off when the machine is left standing for more than a few
minutes.
The tap plungers work horizontally. Push hexagon end in for ON.
Normally, only use the tap on the right hand side of the machine and then the other
side will act as a reserve supply. Always re-fuel as soon as possible after being forced
to call upon the reserve and then, at once, close the "reserve" tap.
It will be noted that, by fitting two petrol feed taps, it is possible to remove the petrol
tank from the machine without the necessity of first draining it of fuel.
STARTING THE ENGINE FROM COLD
Check that there is sufficient fuel in the petrol tank.
Check that there is sufficient oil in the oil tank.
Check that the gear pedal is in the neutral position.
Pull outward the plunger of off-side petrol tap.
Check that the air control lever is in the fully closed position.
Open the throttle not more than one-sixth of the total movement of the twist grip.
Depress the plunger on the top of the carburetter float chamber until it can be felt the
chamber is full of petrol.
SINGLE CYLINDER MODELS
Turn ignition switch to IGN. Open the throttle to the smallest amount possible.
Raise the valve lifter lever and, while keeping it raised, turn over the engine several
times by depressing the kick-starter pedal, three times, the object being to free the
engine. (This only applies if the engine is cold.)
Depress the kick-starter until compression is felt, then raise the valve lifter lever and
ease the engine just over compression. Then, after allowing the kick-starter pedal to
return nearly to its normal position, give it a long swinging kick with the valve closed.
Flywheel momentum will carry over compression and the engine should fire immediately.
If it fails to do so repeat exactly the same process.
TWIN CYLINDER (DE-LUXE MODELS)
Fully advance the ignition, then pull inwards the control lever one-eighth of an inch.
Operate the kick-starter by giving it a long deliberate swinging kick and the engine
should start.
The first slow and gentle movement is essential to avoid damage to the teeth of the
kick-starter pinion.
After the engine has started, slowly open the air lever until it runs evenly. Then set
the throttle so that the engine is running at a moderate speed (neither racing nor ticking
over) and allow to warm up. While doing this, check the oil circulation as detailed in
page 13. The machine can then be taken on the road.
TWIN CYLINDER (STANDARD MODELS)
Turn the switch to IGN, open the throttle to the smallest amount possible. Operate
the kickstarter by giving it a long deliberate swinging kick and the engine should start.
NOTE—Do not race up the engine from cold and do not flood the carburetter to such
an extent that petrol is dripping because then, in the event of a backfire, there
is a danger of such loose petrol igniting. This cannot possibly happen if the
starting instructions are carefully followed, but, in the event of a fire, there is
no cause for panic. Merely turn off the petrol tap to isolate the main supply,
open wide the throttle and turn over the engine by operating the kick-starter
pedal when suction will extinguish the fire.
DRIVING
9

Illustration 2
Showing gear pedal Indica-
tor which upon assembly is
set to record the various
gears also neutral position.
Upon re-assembly after
dismantling for any pur-
pose the indicator pointer
should be correctly re-set
for future reference.
STOPPING THE ENGINE—SINGLES AND STANDARD TWIN
To stop the engine, close the throttle, TURN OFF IGNITION. Before leaving the
machine, turn off the fuel supply.
STOPPING THE ENGINE—MAGNETO MODELS
To stop the engine, close the throttle, depress the magneto cut-out press switch on the
contact breaker cover and keep it depressed until the engine has ceased to revolve.
ON THE ROAD
Having started and warmed up the engine, take the machine off the stand, sit astride it,
free the clutch by pulling up the large lever on the left bar and engage the lowest gear.
Next, slowly release the clutch lever and the machine will commence to move forward.
As it does this, the engine speed will tend to drop as it picks up the load so it will be
necessary to increase the throttle opening, gradually, to keep the engine speed gently
rising.
When well under way, disengage the clutch, slightly close the throttle, engage second
gear and release the clutch lever, then open up the throttle to increase the speed of
the machine. Repeat these operations in order to engage third and top gears.
To engage a higher gear the pedal is pressed downward with the toe and a lower gear is
obtained by raising the pedal with the instep. To engage first gear from the neutral
position, the pedal is therefore raised. After each pedal movement, internal springs
return the pedal to its normal horizontal position.
The pedal must be moved to the full extent of its travel when selecting a gear, either
up or down. It must not be "stamped down" or jabbed, but firmly and decisively
moved till it stops. A half-hearted movement may not give full engagement. Keep
the foot off the pedal when driving and between each gear change because, unless the
lever can freely return to its normal central position, the next gear cannot be engaged.
RUNNING IN THE ENGINE
Selective assembly of parts, such as pistons, cylinders and big end assemblies, etc., are
used in the process of manufacture. It is an established fact that if the engine, when
new, is run in as it should be, engine trouble or seizures will not occur.
It is a natural desire to learn the capabilities of one's machine, similarly it can be irritating
to be overtaken by a rider of a machine fitted with a smaller capacity engine. Never-
theless, the owner of a new machine must, in his own interest, strictly adhere to the
principles of running in, which will result in a quieter engine, with a better performance
than a similar machine owned by a rider who is unwilling to drive with restraint during
the initial stage of running in.
The load imposed on the engine is governed by the amount of throttle that is used, and
the makers of your machine, know from experience, that if the throttle or twist grip is
not opened in excess of one-third ofits total movement for the first 1,000 miles independent
of road speed, the engine cannot be overloaded.
After this distance the amount of throttle can be progressively increased until the
machine has covered 2,000 miles.
10

For convenience a limit mark can be used on the twist grip and grip body.
The recommendation of limiting the road speed to 30 m.p.h. is most unsuitable for
running in, for with this principle the machine could be driven up hill in top gear at
30 m.p.h. and to do so three-quarter or full throttle would be used, which could seriously
and unnecessarily overload the engine.
Special attention must be given, during the running in period, to such details as valve
rocker adjustment, chains, brakes, contact breaker points, and steering head bearings,
all of which tend to bed down in the first hundred miles or so. Particular note must be
made of the adjustment of steering head bearings, which, if run in a slack condition, will
be quickly ruined. After this bedding down process has taken place, adjustments to
such details will only be necessary at lengthy intervals.
Do not overlook instructions for changing oil (see page 24).
NOTES ON DRIVING
If, at first, the lowest gear will not engage, release the clutch lever and after a second or
two, make another attempt. This condition may exist in a new machine, but it tends to
disappear after a little use.
Always endeavour to make the movements of hand (on the clutch) and foot (on the gear
pedal) as simultaneous as possible, and remember, in all gear changes, a steady pressure
of the foot is desirable. This pressure should be maintained until the clutch is fully
released. It is not sufficient just to jab the foot pedal and then release the clutch lever.
When actually in motion, it will be found sufficient to merely free the clutch a trifle,
to ease the drive when changing gear and, with reasonable care, changes of gear then
can be made without a sound.
Do not unnecessarily race the engine or let in the clutch sufficiently suddenly to cause
the rear wheel to spin. Take a pride in making a smooth, silent get-away. .
When changing up to a higher gear, as the clutch Is freed, the throttle should be slightly
closed so that the engine speed is reduced to keep in step with the higher gear ratio.
Conversely, when changing down to a lower gear, the throttle should be regulated so
that the engine speed is increased to keep in step with the lower gear ratio.
Do not slip the clutch to control the road speed.
The clutch is intended to be used only when starting from a standstill and when changing
gear. It must NOT be operated to ease the engine, instead of changing gear, or be held
out, in order to "free-wheel".
The exhaust valve lifter is NOT used in normal driving on main and secondary roads.
When travelling slowly, such as may occur in traffic or on a hill, and the engine commences
to labour, it is then necessary to change to a lower gear. Engine "knocking" or
"pinking" and a harshness in the transmission are symptoms of such labour. A good
driver is able to sense such conditions and will make the change before the engine has
reached the stage of distress. The gear box is provided to be used and consequently
full use should be made of the intermediate gears to obtain effortless running and smooth
hill climbing.
Keep the feet clear of the brake and gear pedals when not actually using them and keep
the hand off the clutch lever when not in use.
Drive as much as possible on the throttle, making the minimum use of the brakes.
When using the machine on wet or greasy roads, It is generally better to apply BOTH
brakes together, because sudden or harsh application of either brake only, under such
conditions, may result in a skid.
In all conditions, it is advisable to make a habit of always using both brakes together
rather than habitually using the rear brake and reserving the front brake for emergency.
11

LUBRICATION
LUBRICANTS TO USE
Efficient lubrication is of vital importance and it is false economy to use cheap oils and
greases. The use of multigrade oils is not recommended.
We recommend the following lubricants to use in machines of our make.
FOR ENGINE LUBRICATION
HOT
above 50° F
SAE SO
Mobiloil D
Castrol Grand Prix
Energol SAE 50
Essolube 50
Shell X-100 Motor Oil 50
COLD
32° F to 50° F
SAE 30
Mobiloil A
Castrol XL
Energol SAE 30
Essolube 30
Shell X-100 Motor oil 30
EXTREME COLD
below freezing point (32° F)
SAE 20
Mobiloil Arctic
Castrolite
Energol SAE 20
Essolube 20
Shell X-100 Motor Oil
20/20W
NOTE—For the British Isles and much of Europe the Cold and Hot recom-
mendations approximate to Winter and Summer conditions re-
spectively. The Extreme Cold recommendations refer to wintry
conditions in parts of Northern Europe, Canada, the Baltic and
Scandinavian countries, and high mountainous districts where ex-
treme cold is the average condition.
FOR GEAR BOX LUBRICATION
HOT
above 50° F
SAE 50
Mobiloil D
Castrol Grand Prix
Energol SAE 50
Essolube 50
Shell X-100 Motor Oil 50
COLD
32° F to 50° F
SAE 50
Mobiloil D
Castrol Grand Prix
Energol SAE 50
Essolube 50
Shell X-100 Motor Oil 50
EXTREME COLD
below freezing point (32°F)
SAE 30
Mobiloil A
Castol XL
Energol SAE 30
Essolube 30
Shell X-100 Motor Oil 30
NOTE—For the British Isles and much of Europe the Cold and Hot recom-
mendations approximate to Winter and Summer conditions
respectively. The Extreme Cold recommendations refer to
wintry conditions in parts of Northern Europe, Canada, the Baltic
and Scandinavian countries, and high mountainous districts where
extreme cold is the average condition.
FOR HUB LUBRICATION AND ALL FRAME PARTS USING GREASE
MP Mobilgrease Castrolease Heavy Energrease C3
Shell Retinax A. or C.D.
FOR TELEDRAULIC FRONT FORKS
Mobiloil Arctic (SAE-20) Castrolite (SAE-20) Energol SAE 20
Essolube 20 (SAE-20) Shell X-100 Motor Oil 20/20W (SAE-20)
FOR REAR CHAINS
Mobilgrease No. 2 Esso Fluid Grease Energrease A.O.
Castrolease Grease Graphited
Heated Until Just Fluid.
When buying oils and greases it is advisable to specify the Brand as well as the grade
and, as an additional precaution, to buyonly in sealed containers orfrom branded cabinets.
12

CHECKING OIL CIRCULATION—ALL MODELS
Provision is made to observe the oil in circulation and it is advisable to do this before
each run.
If the filler cap on the oil tank is removed the end of the oil return pipe will be noticed
below the level of the filler cap orifice and the returning oil can be seen running from
it. This check should be made immediately after starting the engine from cold. This
is because while the engine is stationary, oil from all parts of the interior of the engine
drains back into the crankcase sump, so that, until this surplus is cleared, the return
flow is very positive and continuous. Therefore, if the oil circulation is deranged, the
fact is apparent at once by the lack of a steady return flow.
1
2
3
OUTLET IN OIL RETURN PIPE.
LEVEL INDICATOR LINE.
OIL RETURN PIPE.
4
5
6
OIL FEED PIPE.
OIL FEED GAUZE FILTER.
DRAIN PLUG.
Illustration 3
Interior view of the oil tank showing the metal strainer mounted on the entry
end of the feed pipe union, the return flow pipe from the engine to tank via
the small spout, located so that it can be inspected by removing the tank filler
cap, and air vent pipe, provided to ensure freedom from air-locks.
ENGINE LUBRICATION SYSTEM—SINGLES
This is by dry sump system. Oil feeds, by gravity, from the oil tank to the pump in the
crankcase. The pump forces oil to various parts, which then drains to the bottom of
crankcase sump. The pump then returns oil to the tank. This process is continuous
while the engine is revolving. The pump is so designed that it has a greater capacity
on the return side to that on the delivery side to ensure that all oil is extracted from
the crankcase. A magnetic filter in the sump removes foreign matter collected by
the oil in its passage through the engine. A metal gauze strainer if fitted to the oil
feed pipe in the oil tank to prevent pieces of fluff, etc., which may find their way into
the tank when replenishing, from entering the oil pump. (See illustration 3.) It should
be cleaned in petrol each time the oil tank is drained.
7 VENT PIPE.
13

SEE WARNING ON PAGE 15 BEFORE REMOVAL
Illustration 4
The rotating oil pump plunger is here shown in situ,
together with the guide screw which registers in the
plunger profiled groove, thereby providing the recipro-
cating movement.
1
2
3
4
5
DOWEL PEG, LOCATING TIMING GEAR
COVER.
TIMING SIDE FLYWHEEL AXLE WITH
INTEGRAL GEAR FOR DRIVING OILPUMP
PLUNGER.
OIL PUMP PLUNGER.
SCREW (ONE OF THREE) WITH FIBRE
WASHER, PLUGGING OIL PASSAGES CAST
IN CRANKCASE.
GUIDE PIN, FOR OIL PUMP PLUNGER.
INSERTED RELIEVED TIP DOWNWARD
AS SHOWN.
6
7
8
9
SCREWED BODY TO ACCOMMODATE
THE OIL PUMP PLUNGER GUIDE PIN.
BODY, WITH GUIDE PIN IN POSITION
ENGAGED IN PROFILED CAM GROOVE
OF OIL PUMP PLUNGER.
TAPPED HOLE, FOR PIPE FEEDING OIL TO
OIL PUMP.
TAPPED HOLE, FOR PIPE RETURNING
OIL TO OIL TANK.
14

ENGINE OIL PUMP (see Illustration 4)
The pump has only one moving part. This isthe plunger which revolves and reciprocates.
Rotation is caused by the worm gear on the timing side flywheel axle. Reciprocation
is caused by the guide pin which engages in the profiled groove cut on the plunger.
Oil is fed to the pump through the lower of the two oil pipes between tank and crank-
case and is returned through the upper pipe,
If, for any reason, the crankcase is dismantled the oil pump plunger must be removed
from its housing before attempting to separate the crankcase halves. It is
not necessary to remove the small timing pinion which will pass through in situ.
Important
Under no circumstances must either the pump plunger or guide screw be disturbed
in ordinary routine maintenance.
ENGINE OIL CIRCULATION—SINGLES
The oil pump forces oil through:—
(a) Passages drilled through the timing side flywheel axle, timing side flywheel and crank
pin to lubricate the timing side bearing and the big-end bearing. The splash passes
to interior of cylinder, to lubricate the cylinder and piston, and then falls into the
crankcase sump.
(b) A passage in timing gear case where it "builds up" to a predetermined level to
lubricate the timing gears and then overflows into the crankcase sump.
(c) Through a pipe from the front of oil pump housing to the rocker box by which
all rocker gear and valve stems are lubricated and then falls through the push rod
cover tubes and tappet guides to the timing gear case and, from there, drains into
the crankcase sump, as detailed in (b).
The oil pump extracts oil in the crankcase sump and returns it to oil tank. On its way
it passes the magnetic filter located in the crankcase sump.
ENGINE LUBRICATION SYSTEM—TWINS
This is of the dry sump type. Two separate gear type oil pumps are used, one for
delivery and the other for returning oil to the tank. Oil feeds by gravity to the delivery
pump, by which it is forced, under pressure, to various parts of the engine, from whence
it drains back to the crankcase sump to be collected by the return pump and returned
to the tank. The return pump has a much larger capacity than the delivery pump to
ensure that the crankcase is kept clear of excess oil.
ENGINE OIL PUMPS
Each pump is independently driven, at half engine speed, from the ends of the two
camshafts. They each consist of a pair of close fitting gear wheels in a cast Iron body.
The gears of the delivery pump are considerably narrower than those ofthe return pump,
giving the latter the necessary extra capacity to ensure efficient scavenging.
ENGINE OIL CIRCULATION—TWINS
Oil, from the oil tank, is fed by gravity, through a coarse mesh metal filter, via an external
pipe, to the suction side of the delivery pump, from whence it is discharged, under
pressure, to a large and easily detachable filter that is housed in the crankcase.
After passing through the filter the main supply is directed to the crankshaft centre
bearing and thence, through passages in the crankshaft, to each big-end, the splash from
which provides adequate cylinder lubrication.
The oil supply to rockers and push rods is a by-pass from the main feed, controlled by a
cylindrical block which is rotated by the exhaust camshaft. This is housed in the
driving side crankcase to the right and above the non-return valve. (See illustration 9).
Oil fed to the rocker gear drains into the camshaft tunnels, which have a spill level.
Surplus oil overflows into the timing gear compartment. The four drilled oilways
m the cylinder heads are intentionally restricted by metering plugs. In the event of
an oil shortage to the rocker gear, these oil ways should be checked for obstruction,
Oil is built up in the timing gear compartment to a pre-determined level to lubricate
the train of gears, the surplus flows into the crankcase and is returned to the tank.
A special copper washer is used under the cap covering the rotating block, which must
not be substituted by a different type.
15

Illustration 5
Delivery Oil Pump (on the right)
The level of oil in the supply tank should never be allowed to fall below the low level
mark and, upon replenishment, should not be higher than the upper mark line, at which
level the oil content is 4 pints.
After the first 500 miles, again at 1,000 miles, and subsequently at 5,000 mile intervals,
it is recommended that the oil tank is drained, the oil filter cleaned in petrol and the
tank replenished with new oil.
There are three filters for the oil.
(A) The metal filter located in the feed pipe in the bottom of the oil tank.
This is a thimble shaped filter of coarse metal mesh inserted, from the exterior,
in the short metal feed pipe located in the bottom of the oil tank. It has an open
end finished with a turned over metal ring, located by the oil feed pipe.
Return Oil Pump (on the left)
1
2
3
4
5
6
7
8
9
10
11
12
BALL, FOR NON-RETURN VALVE.
SPRING, FOR NON-RETURN VALVE.
PLUG, RETAINING NON-RETURN VALVE
SPRING AND BALL.
BLEED HOLE.
PLATE, CARRYING OIL FEED AND RE-
TURN PUMPS.
PAPER WASHER FOR OIL RETURN PUMP.
BACK PLATE Of OIL RETURN PUMP.
DOWEL PIN, LOCATING PUMP PLATES
AND BODY.
BODY OF OIL RETURN PUMP.
DOG END OF PUMP GEAR TO ENGAGE
IN END OF CAMSHAFT.
DRIVING GEAR, FOR OIL RETURN PUMP.
DRIVEN GEAR, FOR OIL RETURN PUMP.
13
14
15
16
17
18
19
20
21
22
23
24
FRONT PLATE OF OIL RETURN PUMP.
SCREW (1 OF 6) USED TO RETAIN PLATES
AND BODIES OF OIL PUMPS TO THE
CARRYING PLATE.
BACK PLATE OF OIL FEED PUMP.
DOWEL PIN, LOCATING PUMP PLATES
AND BODY.
DRIVEN GEAR, FOR OIL FEED PUMP.
FRONT PLATE OF OIL FEED PUMP.
SCREWDRIVER SLOT, TO ENABLE DRIVINS
GEAR TO BE CORRECTLY POSITIONED
DURING ASSEMBLY.
DRIVING GEAR, FOR OIL FEED PUMP.
BODY OF OIL FEED PUMP.
BACK PLATE OF OIL FEED PUMP.
PAPER WASHER FOR OIL FEED PUMP.
BLEED HOLE.
THE OIL TANK—ALL MODELS
THE OIL FILTERS
16

(B) The metal filter located in a chamber in the front part of the crankcase and parallel
to the exhaust camshaft.
The crankcase metal filter is made integral with the non-return valve, which|i$ a
sealed unit (see illustration 7). If the valve is difficult to unscrew, do this after a
run or when the crankcase is hot.
(C) The magnetic filter in the crankcase oil sump.
NOTE—Filter B is used on twin cylinder models only.
Illustration 6
Engine Oil Circulation
17

ADJUSTMENT OF OIL FEED (SINGLES)
EXHAUST VALVE STEM LUBRICATION (SINGLES)
CLEANING OIL FILTERS—ALL MODELS
WARNING—Make sure Oil Pipes are not reversed before starting the Engine.
The internal flow of oil is regulated by fixed restrictions. No adjustment is provided
except for the oil feed to the inlet valve stem. This adjustment is made by a needle
pointed screw located in the right side of cylinder head. (See illustration 16). It is
locked in position by a nut. The approximate correct setting is one-sixth of a complete
turn from the fully closed position. Once set it requires little, or no, adjustment.
Inlet valve squeak indicates the oil feed adjustment Is not open enough. Excessive oil
consumption, a smoky exhaust or an oiled sparking plug, generally indicates the oil
feed adjustment is open too much.
The exhaust valve stem is lubricated by oil flowing through a passage drilled in the
cylinder head. No adjustment is provided.
To remove and clean the feed pipe metal filter:
Drain Tank.
Then remove the oil feed pipe from the metal feed pipe protruding from the bottom
of the oil tank.
The metal filter may come away with the feed pipe, in which case there is no need
to disturb it. On the other hand it may remain in the oil tank bottom pipe, in which
case it may be withdrawn by grasping the ringed open end and pulling away.
After removal the filter should be cleaned in petrol and allowed to dry before re-fitting,.
Reverse the above procedure to refit the filter and pipes.
Illustration 7
Twin crankcase filter assembly
18