Royal Enfield METEOR MINOR STANDARD 1958 User manual

WORKSHOP
MAINTENANCE MANUAL
FOR THE
Royal
Enfield
1958—1963
METEOR MINOR STANDARD
METEOR MINOR SPORTS
METEOR MINOR DELUXE
and AIRFLOW
MAN10
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Contents
METEOR MINOR
SECTION A13 ENGINE DATA
SECTION B13 ENGINE SPECIFICATION
SECTION C13 SERVICE OPERATIONS WITH ENGINE IN FRAME
SECTION D11 SERVICE OPERATIONS WITH ENGINE REMOVED
SECTION E8 GEARBOX AND CLUTCH
SECTION F4 MONOBLOC CARBURETTER
SECTION G2j LIGHTING/IGNITION SYSTEM
SECTION G4a BATTERY
SECTION G5d HEAD AND TAIL LAMPS
SECTION H4 FRAME
SECTION J6 FRONT FORK
SECTION K5 FRONT WHEEL 6”
SECTION K7a FRONT WHEEL 7”
SECTION L7 REAR WHEEL (NON DETACHABLE)
SECTION L8 REAR WHEEL (QUICKLY DETACHABLE)
SECTION M6 SPECIAL TOOLS
SECTION P1 AIRFLOW FAIRING
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SECTIONAL VIEW OF 1958 METEOR MINOR ENGINE
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SECTION A13
Technical Data
Meteor Minor Engine
Cubic Capacity ..................... .........496 c.c.
Stroke ....................................... .......64.5 m.m.
Bore ......... .............. Nominal 70 m.m.
Actual 69.874 m.m./2.751 in.
(Rebore to .020 in. when wear exceeds .0065 in.
and again to .040 in. after further .0065 in. wear).
Compression Ratio ... ... ... 8 to 1
Piston Diameter-
Bottom of Skirt-
Fore and Aft. 69.811 m.m.
Top Lands 69.40/69.35 m.m.
Skirt is tapered and oval-turned.
Piston Rings
Width-Plain Rings ................ ... .0625/.0635 in.
Scraper Ring ......................... ... .1550/.1560 in.
Radial Thickness ..................2.883/3.085 m.m.
Gap when in unworn Cylinder .011 / .015 in.
Clearance in grooves .001/ .003 in.
Renew Piston Rings when gap exceeds 1/16 in.
Various oversize Pistons and Rings available.
Piston Boss Internal Diameter ........7499/.7501 in.
Gudgeon Pin Diameter .7499/.7501 in.
ConRod Small End Internal Diameter .7507/.7505 in.
Big End Internal Dia. (1958/59) .....1.8760/1.8755 in.
Big End Internal Dia. (late 1959 on) 2.0215/2.0210 in.
Crank Pin Diameter (1958/59) 1.7715/1.7710in.
Crank Pin Diameter (late 1959 on) 1.8750/1.8745in.
Driving Side Main Ball Bearing
Type ............... ..... ...................S.K.F.6209
Outside Diameter ..................... 85 m.m.
Inside Diameter ..................... 45 m.m.
Width .............. .......................... 19 m.m.
Timing Side Main Roller Bearing-
Type ............... ..... ..................S.K.F. N209
Outside Diameter .. ..................... 85 m.m.
Inside Diameter .... ..................... 45 m.m.
Width .............. ..... ..................... 19 m.m.
Rocker Inside Diameter ............ .5627/.5622 in.
Rocker Bearing Inside Diameter .5622/.5617 in.
Rocker Spindle Diameter ......... .5617/.5615 in.
Inlet Valve Stem Diameter ....... .3430/.3425 in.
Exhaust Valve Stem Diameter... .3410/.3405 in.
Valve Guide Internal Diameter .3437/.3447 in.
Valve Guide External Diameter .6275/.6270 in.
Valve Guide Hole in Cylinder Head Dia. .625/.626 in.
Tappet Stem Diameter ............. .3743/.3740 in.
Tappet Guide Internal Diameter .3755/.3745 in.
Tappet Guide External Diameter 1.0125/1.0130 in.
Tappet Guide Hole in Crankcase Dia 1.011/1.010 in.
Tappet Clearance with cold engine:
Standard, deluxe and sports under normal running
Inlet Nil
Exhaust Nil
Sports models, continuous high speed running
Inlet Nil
Exhaust .005 in.
Valve Spring Free Length
Inner 2.1/32 in. (early) 1.1/2 in. (late)
Outer 2.3/32 in. (early) 1.11/16 in. (late)
(Renew when reduced by 3/16 in. early models
or 3/32 in. late models)
Valve Timing with .012 in. clearance-
Standard and de-luxe models:
Exhaust Opens ... ... 75° before B.D.C.
Exhaust Closes ... 35° after T.D.C.
Inlet Opens ... ... ... 30° before T.D.C.
Inlet Closes ... ... ... 60° after B.D.C.
Sports models:
Exhaust Opens ... ... 83° before B.D.C.
Exhaust Closes ... 35° after T.D.C.
Inlet Opens ... ... ... 30° before T.D.C.
Inlet Closes ... ... ... 60° after B.D.C.
Camshaft Bearing External Diameter .9095/.9085 in.
Camshaft Bearing Internal Diameter .7505/.7495 in.
(Bored in position in crankcase)
Inlet cam Lift (All models) .3125 in.
Inlet valve Lift (All models) .3125 in.
Exhaust cam Lift (Standard + de-luxe) .3125 in.
Exhaust valve Lift (Standard + de-luxe) .3125 in.
Exhaust cam Lift (Sports models) .328 in.
Exhaust valve Lift (Sports models) .328 in.
Timing Sprocket ............. ..............12 Teeth
Camshaft Sprocket ......... ..............24 Teeth
Distributor Sprocket ....... ..... .........15 Teeth
Timing Chain-Type Single No. 110038 endless
Length ... ........... 66 pitches
Width ... ........ .225 in.
Pitch ... ........ .375 in.
Roller ... ........ .250 in.
Distributor chain-Type Single No. 110500 endless
Length .............. 40 pitches
Width ... ........... 8.64 m.m.
Pitch ... ........... 8 m.m.
Roller ... ........... 5 m.m.
Distributor Speed ... ......... .....Half Engine Speed
Points ... ......... ..... .015 in.
Timing Advanced 3/8 in.-7/16 in. before T.D.C.
Timing Retarded 1/32 in. before T.D.C.
Engine Sprocket 29 Teeth
Clutch Sprocket ........... ............... 56 Teeth
Final Drive Sprocket (Solo) ... ...... ... 19 Teeth
Primary Chain Type Duplex No. 114038 endless
Length 92 pitches
Width .......... ......... ............ .628 in.
Pitch ............ ......... ..........… .375 in.
Roller .......... ......... ......................250 in.
Feed Oil Pump-Speed .............1/6 Engine Speed
Piston Diameter .24975/.24950 in.
Stroke ... ... .5 in.
Return Oil Pump-Speed .. 1/6 Engine Speed.
Piston Diameter .375.3755 in.
Stroke ... ... .5 in.
Spark Plug: Up to engine No. SMCA 7027
(short reach) Champion L10S
Frome engine No. SMCA 7028
(long reach) Champion NA8
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SECTION A13
Technical Data
Meteor Minor Engine
Cubic Capacity ..................... .........496 c.c.
Stroke ....................................... .......64.5 m.m.
Bore ......... .............. Nominal 70 m.m.
Actual 69.874 m.m./2.751 in.
(Rebore to .020 in. when wear exceeds .0065 in.
and again to .040 in. after further .0065 in. wear).
Compression Ratio ... ... ... 8 to 1
Piston Diameter-
Bottom of Skirt-
Fore and Aft. 69.811 m.m.
Top Lands 69.40/69.35 m.m.
Skirt is tapered and oval-turned.
Piston Rings
Width-Plain Rings ................ ... .0625/.0635 in.
Scraper Ring ......................... ... .1550/.1560 in.
Radial Thickness ..................2.883/3.085 m.m.
Gap when in unworn Cylinder .011 / .015 in.
Clearance in grooves .001/ .003 in.
Renew Piston Rings when gap exceeds 1/16 in.
Various oversize Pistons and Rings available.
Piston Boss Internal Diameter ........7499/.7501 in.
Gudgeon Pin Diameter .7499/.7501 in.
ConRod Small End Internal Diameter .7507/.7505 in.
Big End Internal Dia. (1958/59) .....1.8760/1.8755 in.
Big End Internal Dia. (late 1959 on) 2.0215/2.0210 in.
Crank Pin Diameter (1958/59) 1.7715/1.7710in.
Crank Pin Diameter (late 1959 on) 1.8750/1.8745in.
Driving Side Main Ball Bearing
Type ............... ..... ...................S.K.F.6209
Outside Diameter ..................... 85 m.m.
Inside Diameter ..................... 45 m.m.
Width .............. .......................... 19 m.m.
Timing Side Main Roller Bearing-
Type ............... ..... ..................S.K.F. N209
Outside Diameter .. ..................... 85 m.m.
Inside Diameter .... ..................... 45 m.m.
Width .............. ..... ..................... 19 m.m.
Rocker Inside Diameter ............ .5627/.5622 in.
Rocker Bearing Inside Diameter .5622/.5617 in.
Rocker Spindle Diameter ......... .5617/.5615 in.
Inlet Valve Stem Diameter ....... .3430/.3425 in.
Exhaust Valve Stem Diameter... .3410/.3405 in.
Valve Guide Internal Diameter .3437/.3447 in.
Valve Guide External Diameter .6275/.6270 in.
Valve Guide Hole in Cylinder Head Dia. .625/.626 in.
Tappet Stem Diameter ............. .3743/.3740 in.
Tappet Guide Internal Diameter .3755/.3745 in.
Tappet Guide External Diameter 1.0125/1.0130 in.
Tappet Guide Hole in Crankcase Dia 1.011/1.010 in.
Tappet Clearance with cold engine:
Standard, deluxe and sports under normal running
Inlet Nil
Exhaust Nil
Sports models, continuous high speed running
Inlet Nil
Exhaust .005 in.
Valve Spring Free Length
Inner 2.1/32 in. (early) 1.1/2 in. (late)
Outer 2.3/32 in. (early) 1.11/16 in. (late)
(Renew when reduced by 3/16 in. early models
or 3/32 in. late models)
Valve Timing with .012 in. clearance-
Standard and de-luxe models:
Exhaust Opens ... ... 75° before B.D.C.
Exhaust Closes ... 35° after T.D.C.
Inlet Opens ... ... ... 30° before T.D.C.
Inlet Closes ... ... ... 60° after B.D.C.
Sports models:
Exhaust Opens ... ... 83° before B.D.C.
Exhaust Closes ... 35° after T.D.C.
Inlet Opens ... ... ... 30° before T.D.C.
Inlet Closes ... ... ... 60° after B.D.C.
Camshaft Bearing External Diameter .9095/.9085 in.
Camshaft Bearing Internal Diameter .7505/.7495 in.
(Bored in position in crankcase)
Inlet cam Lift (All models) .3125 in.
Inlet valve Lift (All models) .3125 in.
Exhaust cam Lift (Standard + de-luxe) .3125 in.
Exhaust valve Lift (Standard + de-luxe) .3125 in.
Exhaust cam Lift (Sports models) .328 in.
Exhaust valve Lift (Sports models) .328 in.
Timing Sprocket ............. ..............12 Teeth
Camshaft Sprocket ......... ..............24 Teeth
Distributor Sprocket ....... ..... .........15 Teeth
Timing Chain-Type Single No. 110038 endless
Length ... ........... 66 pitches
Width ... ........ .225 in.
Pitch ... ........ .375 in.
Roller ... ........ .250 in.
Distributor chain-Type Single No. 110500 endless
Length .............. 40 pitches
Width ... ........... 8.64 m.m.
Pitch ... ........... 8 m.m.
Roller ... ........... 5 m.m.
Distributor Speed ... ......... .....Half Engine Speed
Points ... ......... ..... .015 in.
Timing Advanced 3/8 in.-7/16 in. before T.D.C.
Timing Retarded 1/32 in. before T.D.C.
Engine Sprocket 29 Teeth
Clutch Sprocket ........... ............... 56 Teeth
Final Drive Sprocket (Solo) ... ...... ... 19 Teeth
Primary Chain Type Duplex No. 114038 endless
Length 92 pitches
Width .......... ......... ............ .628 in.
Pitch ............ ......... ..........… .375 in.
Roller .......... ......... ......................250 in.
Feed Oil Pump-Speed .............1/6 Engine Speed
Piston Diameter .24975/.24950 in.
Stroke ... ... .5 in.
Return Oil Pump-Speed .. 1/6 Engine Speed.
Piston Diameter .375.3755 in.
Stroke ... ... .5 in.
Spark Plug: Up to engine No. SMCA 7027
(short reach) Champion L10S
Frome engine No. SMCA 7028
(long reach) Champion NA8
EXPLODED VIEW OF METEOR MINOR ENGINE (EARLY)
Fig 1.
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Section B13 Page 1
SECTION B13
Engine Specification
" Meteor Minor "
1. Engine
The engine is an even-firing vertical twin
cylinder, having separate cylinders and heads
and fully enclosed pressure-fed overhead valve
gear. It has dry sump lubrication with the oil
tank integral with the 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 70 m.m., the stroke being 64.5
m.m. The cubic capacity of the engine is 496
c.c. The cylinder heads are located on the
cylinders by hollow dowels.
4. Pistons
The high compression pistons are of low
expansion aluminium alloy, heat treated and
form-turned oval and having split skirts. The
compression ratio is 8 to 1. There are three
piston rings, the top two of which are
compression rings. Both are taper ground and
the top one is chromium plated. The third ring is
for oil control and is slotted.
5. Connecting Rods
The connecting rods are produced from
stampings 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, secured by cotter pins.
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 graphite cast iron. The total
weight is 22.1/2lbs. and it is carefully balanced.
The main journals are ground and the big end
journals are ground and hand-lapped. The main
journal on the drive side of the later type
crankshaft is drilled through its centre for
situation and operation of 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 with silencing ramps to ensure
quiet running. (The exhaust cams on the sports
cams do not have these silencing ramps).
10. Valves
The inlet valves are machined from
stampings of special Silicon-Chrome Valve
Steel and the exhaust valves are of austenitic
steel.
11. Valve Gear
The valves are operated from the camshafts
by means of large flat based guided tappets,
tubular alloy push rods and overhead rockers.
Two compression springs are fitted to each
valve.
12. Timing Drive
The camshafts are located in the crankcase,
running in bronze bushes. They are driven by a
common, 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.
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Section B13 Page 2
The distributor 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 distributor fixing bolts
in their slotted holes.
13. Ignition and Lighting System. (See
Section G)
Separate systems are provided for ignition
and lighting. The distributor is chain driven from
the inlet camshaft at half engine speed and has a
built-in automatic advance mechanism.
Lighting current is supplied by the battery
which is charged through a rectifier from an
alternator consisting of a rotating magnet
mounted on the crankshaft and running in a
six-coil stator in the primary chaincase.
14. Carburettor. (See Section F)
Amal Monobloc Type 376/92 Bore 1.1/16in.
Main Jet ......250
Needle Jet ......106
Pilot Jet ......30 c.c.
Throttle Valve ......No. 3½
Needle Position ......No. 2
Pilot Outlet .......025 in.
15. Air Filter
The air filter is a Vokes Micro-Vee felt and
gauze dry filter, 5 in. diameter and housed in a
compartment of the toolbox.
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 1/6engine 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
baffle from being drawn up by the flywheel.
The oil from the rocker bearings is squirted
through a small hole in the rocker on to the top
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Section B13 Page 3
end of the pushrod. It flows down the push rod
into the cam tunnel where it lubricates the cams
and tappets and thence into the timing chest,
lubricating the timing chains. There are small
holes from the inlet cam tunnels through the
cylinder walls for the purpose of lubricating the
skirts of the pistons and a hole from the inlet
cam tunnel into the timing chest through which
surplus oil from the inlet rockers passes. The
exhaust cam tunnel, however, has no hole but is
kept full of oil to ensure adequate lubrication of
the exhaust cams and prevent wear. The oil
level is maintained to a height in the groove in
the tappet guide where a hole is drilled in to the
timing chest, through which surplus oil from the
exhaust rockers passes.
Both pumps are double acting, one side of
the feed pump supplying the big ends only and
the other side the rockers and valve gear. In a
similar manner one side of the return pump
pumps the big end oil back to the tank from the
crankcase and the other side the valve gear oil
back to the tank from the timing chest.
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 the feed oil
leaving the tank and there is a large capacity felt
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 suspended in the
oil.
17. Breather
The efficient operation of the breather is of
paramount importance to the performance of the
engine. It acts as a non-return valve between the
crankcase and the outside atmosphere, causing a
partial vacuum in the crankcase and rocker
boxes which prevents the passage of oil into the
cylinders and consequent smoking and oiling of
the plugs.
On early models the breather is located on
the driving side of the crankcase and consists of
a small housing attached to the crankcase by
three screws and having a short rubber tube
with flattened end, which acts as a non-return
valve.
On later models the housing contains two
pen-steel discs covering two holes drilled in the
crankcase. Accurate seating of the discs is
ensured by a pen-steel plate held between the
breather body and the crankcase.
In addition a breather, in the form of a pen
steel disc, is situated in a recess in the head of
the special bolt, which secures the alternator
rotor on to the end of the crankshaft. This bolt is
drilled throughout its length, and communicates
crankcase pressure to the breather via the hole
drilled through the drive side main journal.
A plug screwed into the head of the bolt
retains the disc, and a hole drilled in its centre
allows the crankcase to breath in to the primary
chaincase.
A vent pipe fitted to the top of the primary
chaincase has its aperture inside the case
shielded by a baffle from the oil flung from the
chain. (See section C, fig 7)
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 Section
E). The standard gear ratios are as follows :-
Early Late
Bottom Gear ......13.00 13.00
Second Gear ........ ......8.42 8.60
Third Gear ........... ......6.08 6.37
Top Gear .............. ......4.67 4.67
19. Clutch
The clutch has 5 pressure plates and four
friction plates, including the sprocket which is
lined on both sides with friction material. The
other friction plates have Klinger inserts or/and
bonded on friction material, which give smooth
operation and freedom from slipping in the
presence of oil.
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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 the housing is uncovered
and oil below the disc in the housing is forced through
W to the rocker gear.
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.
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 timing chest.
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 timing chest.
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.
Section B13 Page 4
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Section C13 Page 1
SECTION C13
Service Operations with Engine in Frame
"Meteor Minor"
1. 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 plug is 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 engine is turned gently forwards while the
cover is being put into place. This will help the
engagement of the pump worm with the pump
spindle and prevent damage to the gears.
Always fill the filter with clean oil before
refitting the timing cover and always take great
care not to damage the gasket where the section
is narrow.
To verify that the oil pumps are working
after replacing the timing cover, start the engine
and 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 circulating. 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.
2. Valve Timing
The camshaft sprockets are keyed to the
camshafts so that the valve timing can only be
incorrect if the timing chain is incorrectly fitted.
The correct setting is obtained with the
marks stamped on the camshaft sprockets facing
each other inwards on the centre line and the
mark on the crankshaft sprocket pointing
vertically downwards. If it is necessary to
remove the sprockets see Subsections 23 and
24.Remember that all three timing sprocket
fixing bolts have Left-Hand Threads. While
tightening the camshaft bolts, the sprockets
should be held.
The correct valve timing at .012 in. tappet
clearance is as follows:
Standard and de-Luxe models:
Exhaust opens ......75° before B.D.C.
Exhaust closes ......35° after T.D.C.
Inlet opens ..............30° before T.D.C.
Inlet closes ..............60° after B.D.C.
Sports model:
Exhaust opens ......83° before B.D.C.
Exhaust closes ......35° after T.D.C.
Inlet opens ..............30° before T.D.C.
Inlet closes ..............60° after B.D.C.
3. Tappet Adjustment
The tappet clearance is adjusted by means of
a screw in the outer end of the rocker. Access to
the adjusting screws is obtained by removing
the covers of the rocker boxes.
The clearance between the end of the screw
on the valve stem cap should be nil, or as little
as possible, with the engine COLD, for all
Meteor Minors, and for continuous high-speed
work with the Sports model a clearance of .005
in. is recommended on the exhaust valves.
To adjust the clearance, loosen the locknut
beneath the rocker arm, turn the screw with a
small spanner and retighten the locknut.
The adjustment for each valve should be
made with the corresponding valve of the other
cylinder fully open. This ensures that the tappet
is well clear of the ramp which is located on
either side of the cam to reduce valve noise.
If, after long service, the valve stem cap or
the rocker adjusting screw are found to be worn,
they should be renewed, as uneven thrust due to
the screw being in a different position after
adjustment may cause lateral movement of the
rocker giving rise to a sharp tapping noise.
4. Ignition Timing
Before setting the timing, remove the cover
and rotor arm of the distributor and adjust the
contact breaker points to a clearance of .015 in.
when fully opened. If the contacts are worn or
pitted refer to Section G.
Because of the auto-advance mechanism, the
timing is normally in the "retard" position when
the engine is stationary, and the timing is set so
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