Villiers Workshop Manual 9e 2l 3l 31c 32a 24a – PDF DOWNLOAD

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Foreword . . .

UALITY and the ability to give long and reliable service are the primary considerations in the production of all Villiers engines, but when servicing eventually becomes necessary it is very important that the correct tolerances are maintained and it is, therefore, essential that only genuine Villiers spares are used.

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The power units covered by this manual are the 148 c.c., 173 c.c., 197 c.c. and 246 c.c. engine-gear units adopted as standard equipment by the leading manufacturers of motor cycles, motor scooters, etc. The models tre the Marks 31C, 2L, 3L, 9E and 32A, 34A respectively, the basic specifications being for motor cycle power units. All models are available with either three or four-speed gearbox, and for kcooter applications where the power unit is more-or-less enclosed, a fan with cowling is provided. Normally, starting the engine is by kickstarter, but all models are available having the SIBA " Dynastart " unit giving either uni-directional rotation only, or reversing rotation in addition.

Routine maintenance and lubrication are fully dealt with in the Rider's Handbook and is not repeated in these pages, but it is recommended that the reader obtains copies of both the User's Handbook V.E.C.542 and Illustrated Spare Parts List V.E.C.545 with complete " exploded " drawings which used in conjunction with this Manual will, we believe, prove invaluable. It is also suggested that the following literature is obtained from Villiers Service Department :— Service Bulletins M/C34, 35, 37, 39, 43, 46, 47, 48, 49, 50.

Service Instructions SIBA " Dynastart " V.E.C.549 Sheets 1-9.

Ignition Test Unit Model M.3089 V.E.C.27.

Every engine is built to a works specification, the number of which is stamped on the nameplate attached, usually to the inner chaincase. This number, together with the serial number, should be quoted in any correspondence in connection with repairs or replacement parts. Our Service Department will gladly deal with any problems in connection with Villiers products.

WORKSHOP MANUAL

Marks 9E, 2L, 3L, 310, 32A & 34A (197 c.c.)

(173 c.c.)

(148 c.c.)

(246 c.c.)

ENGINE - GEAR UNITS for

MOTOR CYCLES and SCOOTERS

â– 1/5 11

THE VILLIERS ENGINEERING CO. LTD., MARSTON ROAD Telephone: 22399 (20 lines).

WOLVERHAMPTON

ENGLAND

Telegrams: Villiers Wolverhampton.

I/ II■•

TECHNICAL DATA Mk. 2L Mk. 9E Mk. 31C Cylinder Bore, ... 59 mm=2.3235"/2.3230" 59 mm=2.324"/2.3235" 57 mm=2.245"/2.2445" Standard Cylinder Bore, ... As above plus .015" or .030" Oversize 63.5 mm=2.5" 58 mm=2.283" ... 72 mm=2.834" Stroke ...

173 cc= 10.55 Cu. ins. ... 197 cc= 12.03 Cu. ins.

Capacity 148 cc---9.03 cu. ins.

Compression Ratio, 7.4: 1 7.75: 1 ... 7.25: 1 Standard Compression Ratio, ... 8.25: 1 Sports 20 teeth x i" pitch 20 teeth x i" pitch 20 teeth x ir pitch Engine Sprocket 43 teeth x i" pitch 43 teeth x i" pitch Clutch Sprocket 43 teeth x i" pitch Primary Drive ... 2.15: 1 2.15:'!

2.15: 1 Ratio " Rend(' " No. 110 038 x 58 pitches Primary Chain ...

3-speed box 1, 1.34, 2.5.5: 1 Gearbox Ratios, Standard ...

Wide 3-speed box 1, 1.7, 3.25: 1 „ Standard ...

4-speed box 1, 1.27, 1.78, 2.94: 1 . „ Wide 4-speed box 1, 1.34, 2.4, 3.6: 1 Final Drive 17 teeth 18 teeth 16 teeth Sprocket, Std. To suit " Renold " Chain No. 110 046 3:" pitch x .305" wide Alternative Sprockets available from 15 to 20 teeth 24" 21" Final Chain Line 24" All " Villiers " threads are Right-hand unless otherwise stated. ff

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BALL AND ROLLER BEARINGS

Driving Shaft, L.H. Outer ...

Driving Shaft, L.H. Inner ...

Driving Shaft, R.H. Gearbox Mainshaft Crankpin Roller, Standard ...

Crankpin Roller, Sports Crankpin Diameter, standard Crankpin Diameter, 0/S Connecting Rod Big End Diameter, Standard ...

Connecting Rod Big End Diameter, Oversize Connecting Rod Side Clearance, Total ... page 2

20 x 47 x 14 mm No. 6204 3 spot ball bearing 20 x 52 x 15 mm No. 6304 3 spot ball bearing 25 x 52 x 15 mm No. R.125 roller bearing 25 x 52 x 15 mm No. 6205 2 spot ball bearing r dia. x r long, 26 per set +." dia. x TV," long, 9 per set used with cage .7983"/.7980" .7993"/.7990" 1.2986"/1.2981" 1.2996/1.2991" .009"/.005"

SMALL END BEARINGS

.493"/.4927" ... _ Gudgeon Pin, Diameter .4935"/.4930" Gudgeon Pin Bush, in Piston Gudgeon Pin Bush, in Connecting Rod .4936"/.4931" Mk. 31C Mk. 9E, Mk. 2L. PISTON AND PISTON RINGS 2.245" Dia. Compression Ring, Standard Size ... 2.3235" dia. .008"/.012" ... .008"/.012" ...

End Gap, in Position ... .03" ... .03" Maximum Permissible Gap ... .0042"/.0022" Ring Clearance in Groove, Total .... 0062"/.0042" ... Standard Plus .015" and Standard Plus .030" ...

Oversize Piston Rings ...

Piston Skirt Clearance in Cylinder Bore MM. .0047" (Mk. 9E and Mk. 2L) .0041" (Mk. 31C) CARBURETTER Villiers Type ... S.25, Mk. 9E Taper Needle, ... No. 31 Standard Needle Setting, ... 1.95" out Standard Throttle, Standard No. 3 Main Jet, Standard ... 120 c.c.

Pilot Jet, ... 35 c.c.

Standard

S.22, Mk. 2L

S.19, Mk. 31C

No. 31

No. 31

No. 4 groove No. 24

2.06" out No. 21

135 c.c.

80 c.c.

35 c.c.

35 c.c.

IGNITION

Contact Breaker Point Gap ...

Points Commence to Open v .

Sparking Plug ...

Sparking Plug Gap ...

.012"/.015" (Villiers Magneto) iy"—*" before top dead centre " Lodge " HH.14 .018"i.025"

LIGHTING SETS

Rectifier Type, 6 Volt, Wiring ... M. 2689D ...

Diagram Rectifier Type, 12 Volt, Wiring M.2808D ...

Diagram Direct Type, 6 Volt, Wiring Diagram M.2742D LUBRICATION

Engine ...

Gearbox Chaincase

Petroil mixture. For the first 500 miles, 1 part Castro] XL (S.A.E.30) oil to 16 parts petrol, and subsequently 1 part to 20 parts.

Castrol XL (S.A.E.30) oil. Fill to oil level plug. ... Castrate (S.A.E.20) oil. Fill to oil level plug. page 3

TECHNICAL DATA Cylinder Bore, Standard Cylinder Bore, Oversize ... ...

Stroke ...

-.

Capacity Compression Ratio ... ' Engine Sprocket, 5' pitch Clutch Sprocket, II' pitch Primary Drive Ratio ...

Primary Chain, "Renold" ...

No. 110 038 Gearbox Ratios ...

Final Drive Sprocket ...

... ... ...

... ... ... ... ...... ... ... ... ... ... ...

Mk 32A Mk 34A 66 mm=2.6006"/2.6001' 66 mm As above plus .015" or .03" 72 mm 72 mm=2.834" 246 c.c.

246 c.c.=15 Cu. ins.

7.9-1 12-1 25 teeth 20 teeth 43 teeth 43 teeth 1.72-1 2.15-1

Mk 3L 59 nun=2.324"/2.3235" 63.5 mm=2.5" 173 c.c. =10.55 cu. ins.

7.4-1 20 teeth 43 teeth 2.15-1

...... 60 Pitches 58 Pitches 58 Pitches ... ... I, 1.27, 1.78, 2.94-1 1, 1.27, 1.78, 2.55-1 1, 1.27, 1.78, 2.55-1 15 teeth ... ... 15 teeth 17 teeth To suit " Renold " Chain No. 110 046, 5" pitch x .305" wide — 25" 24' 24' Final Chainline NOTE:—ALL VILLIERS THREADS ARE RIGHT-HAND UNLESS OTHERWISE STATED. BALL AND ROLLER BEARINGS Driving Shaft, left-hand, outer ... 20 x47 x 14 mm No. 6204, 3 spot ball bearing Driving Shaft, left-hand, inner ... 20 x 52 x 15 mm, No. 6304, 3 spot ball bearing Driving Shaft, right-hand, inner ... 25 x 52 x 15 mmuNo. R.125, roller bearing Driving Shaft, right-hand, outer ... 20 x52 x 15 mm, No. R320, roller bearing (Mk 3LSF only) Gearbox Mainshaft ... .-- 25 x 52 x 15 mm, No. 6205, 2 spot ball bearing — 94' diW x -116-" long 264" dia. x 4' long Crankpin Roller ... ... ... 94" dia. x 156-' Ion ... .7983"/.7980" .7983"/.7980 Crankpin Diameter, Standard ... .7993"/.7990" .7993"/.7990 Crankpin Diameter, Oversize I Mks 32A and 34A Con Rod Big End Diameter, Standard 1.2996"/1.2991' 1.2986"/1.2981" Con Rod Big End Diameter, Oversize 1.3006/1.3001" I 1.2996'/1.2991" Con Rod Side Clearance, Big End ... .009"/.005" total J .009'7.005" total SMALL END BEARINGS .493"/.4927' Gudgeon Pin Diameter ...

Gudgeon Pin Bush, in Piston ... .4935"/.4930' dia.

Gudgeon Pin Bush, in Con Rod ... .4936'7.4931' dia.

Mks 32A, 34A and 3L

PISTON AND PISTON RINGS 2.6006' dia.

Compression Ring, Standard Size ... 2.6006" dia.

2.3235' dia. .012"/.008" End Gap, in position ...

Maximum Permissible Gap ... .03" Mks 32A, 34A and 3L .0062'7.0042" total Ring Clearance in Groove ... ... Standard plus .015" and .03" Oversize Compression Ring Piston Skirt Clearance in Cylinder ....0048' min. total 2.6006" dia. .0041' min.

The expander ring, behind bottom compression ring, is not fitted to the Mk 34A engine.

CARBURETTER ...

Type ...

...

...

Mk 32A ... Villiers S.25/6

... ...

... ...

... ...

... 1" dia. ... No. 34-1.85" out

...

...

...

...

Choke ...

Needle ...

Throttle Main Jet Pilot Jet IGNITION

'

page 4

140 c.c.

Mk 34A Mk 3L Amal " Monobloc" Villiers S.22/3 Ref. 389/39 1--*" dia. i" dia.

Type Din No. 3 No. 3I-No. 4 groove groove No. 34 No. 25 370 c.c.

135 c.c.

Needlet Jet No. 109 35 c.c.

Mk 32A and 34A Units Villiers Flywheel Magneto 6 Volt Lighting Coils Armature Assembly, Code No. A.139 Flywheel Assembly, Code No. R.134 Contact Breaker Point Gap .0121.015' Points Commence to Open 4"--31-" BEFORE TOP DEAD CENTRE Sparking Plug Mk 32A, Lodge HH14 Sparking Plug Mk MA, Lodge RL47 or RL49 Sparking Plug Mk 34A, running in Lodge 2HLN

TECHNICAL DATA—cont.

Mk 3L UNIT " SIBA " Dynastart Unit, Uni-Directional Rotation, 12 volt, Contact Breaker Point Gap .0227.020" with Cam FCDX/1 Points Commence to Open 11/64" BEFORE top dead centre.

LUBRICATION Mks 32A and 3L Units Engine:—Petroil mixture for first 500 miles, 1 part Castro! XL (S.A.E.30) oil to 16 parts petrol and subsequently 1 part to 20 parts.

Mk MA Unit Engine :—Petroil mixture, 1 part Castrol " R" oil to 24 parts 80 octane petrol.

Mks 32A, MA and 3L Units Gearbox :—Castrol XL (S.A.E.30) oil, fill to oil level plug.

Chaincase:—Castrolite (S.A.E.20) oil, fill to oil level plug.

For some customers the specification calls for the modified gear-change control shown below and for which a different gearbox and cover is required. The gear-change mechanism is retained in end cover by a circlip on gear-operating spindle. This modified gearchange is fitted to all Mark 3L units. Should it be necessary to dismantle in order to fit

RATCHET & QUADRANT ASSY. LEFT .•

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new components, make sure that the left-hand pawl is fitted first on the fulcrum pin. Both pawls are alike, but as the left-hand pawl is subjected to greater loading, this should always be fitted first to avoid excessive overhang.

CLUTCH For the Mark 3L unit the clutch is exactly as fitted to the Mark 9E model, but for the Mark 32A and Mark 34A models additional springs are fitted inside three of the standard springs to give greater contact pressure of the clutch plates.

SPINDLE ASSY.

GEAR CONTROL SPRING

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!

RIGHT HAND PAWL PAW LS SPRING

GEAR-CHANGE CONTROL

CARBURETTER The carburetter used with the Mark 3L is the Villiers Type S.22/3 and for the Mark 32A the Type S.25/6. These carburetters are similar in construction to the Type S.25/ fitted to the Mark 9E unit. The Mark 34A unit, however, has the AMAL " Monobloc " carburetter, ref. 389/39. Details of jets, settings, etc., are given on the data sheet, but the owner should obtain copies of AMAL "Hints and Tips" list No. 502, Issue No. 5, and spares list No. 503, Issue No. 5, for fuller information. page 5

Cradle ST 2549

5SB)

DISMANTLING When a major overhaul is necessary, calling for dismantling of crankcase and/or gearbox, the complete unit must be removed from motor cycle frame and mounted in a fixture or cradle as illustrated above. To facilitate removal of engine disconnect the complete exhaust system using " C " spanner E.8678 for 9E or E.8676 for 2L and 31C models. If carburetter is not be be dismantled, remove it, with control and inlet pipe attached, from cylinder and secure out of the way to machine frame.

The " HYDRACLAMP," to which the cradle ST.2549 is fixed, is bolted to the work bench; this fitting, an optional extra, allows page 6

unit to turn a full circle and to swing thus bringing crankshaft and gearbox mainshaft vertical to facilitate fitting of clutch assembly, and timing or inspection of contact breaker.

The " HYDRACLAMP " (Ref. No. HSSB) is provided with a head to which can be bolted the bottom member of the cradle.

CYLINDER HEAD AND CYLINDER

Remove spark plug and decompressor, if fitted, from cylinder head, then four fixing bolts and washers. A slight sideways tap may be necessary to break cylinder head joint, after which head and joint washer is removed.

Now remove cylinder base fixing nuts and spring washers, and lift cylinder clear of piston.

Do not twist cylinder round piston, otherwise damage to piston rings may occur should ends foul the edges of cylinder ports. As cylinder comes free of piston do not let piston skirt swing against the connecting rod; if this is allowed the skirt will possibly be distorted.

Remove paper joint washer and rest piston on SUPPORT PLATE, ST.2535D, so that bottom of skirt is not damaged against the crankcase.

up. Gap between ends of compression rings when new and in position in the cylinder, is .008"/.012". When wear increases gap to .03" ring should be replaced, and if it is found that with a new ring gap is more than .012" this indicates a worn cylinder bore. Any cylinder having a bore of .008" or more above the original size should be replaced by an oversize cylinder and piston, stock rebore sizes being plus .015" or plus .030". The piston should always be replaced as originally

Fig 1

---------.

Fi g 3 Piston Support Plate ST 253513

1

fitted, the top of the crown being marked "FRONT "; if fitted wrong way round ring ends may foul cylinder port openings.

PISTON Use a pair of thin-nosed pliers to take out one gudgeon pin circlip, push gudgeon pin clear of connecting rod small end bush and lift off piston. If carbon dposits prevent removal of gudgeon pin by hand, use an extractor of the band type as illustrated.

41,._M .1111

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Fig.

s---------_----, L '---..-= a-S 1 N. %... ,

Extractor

Compression rings can be removed without risk of damage by introducing behind them three pieces of thin brass strip, equally spaced, then sliding off rings, Fig. 4. Do not scratch the piston. It is desirable to refit each ring in its original groove.

2

—

'

II

-

M

4 4.4. . . . ._ ,

A steel expander ring, fitted behind the lower compression ring, centralises piston in bore of cylinder, thereby eliminating noise caused by piston slap whilst engine is warming

REMOVAL OF OUTER CHA1NCASE The outer chaincase is retained by a hexagon cap nut and located by a small dowel at the rear end. When the cap nut is removed page 7

chaincase can be eased off stud and dowel, and lifted clear exposing engine sprocket, primary chain and clutch assembly.

used for both end cap and centre nut removal, and it is not necessary to disturb the push rod adjuster screw fitted in the centre of the end

CLUTCH, PRIMARY DRIVE AND FINAL DRIVE SPROCKET The drive from engine to clutch on gearbox mainshaft, is by endless pre-stretched .11 inch pitch roller chain, RENOLD No. 110 038, 58 pitches. The chain and clutch run in an oil bath formed by the outer and inner chaincase halves, a gasket being fitted between joint faces. Oil filler and level plugs are fitted, the former having a vent hole. Oil is prevented from escaping at engine end by a paper gasket between the inner half of chaincase and crankcase and at rear, or clutch end by a rubber seal fitted in inner chaincase and which is in contact with the ground extension of the gearbox high gear pinion. In earlier models the seal consisted of a felt washer, held in position by a plate and four rivets.

The two types of seal are not interchangeable.

REMOVAL OF CLUTCH, PRIMARY CHAIN AND ENGINE SPROCKET Lock engine and clutch sprockets by means of ST.1380 (see Fig. 5) and using peg spanner ST.2552 unscrew clutch end cap anti-clockwise, thus releasing clutch plates and exposing the centre nut. On earlier Mk. 9E units,

14141401\191 Fig 6 Peg Spanner ST 9362

cap. Later clutches have nine springs and the centre nut has a hexagon flange, removal being by a tubular box spanner, Ref. EM.548.

: i8 ,

7

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-------- -4

Box Spanner EM 548 For removal of end cap on later units peg spanner ST.2552 should be used in conjunction with" Hammertight "spanner, Ref. M.1239E. When using peg spanner ST.2552 it is first necessary to remove the clutch rod adjuster screw from end cap so that centre bolt of spanner can be screwed into the tapped hole.

When the clutch is originally assembled, one or more shims may be fitted in end cap; the number and thickness of the shims should be noted at the time, and the same shims replaced when re-building if original clutch plates are used.

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)

ctl

Fig 5

Sprocket Locking Plate ST 1380

111)

1.4

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eilL d s•-w. 1/

Peg Spanner ST 2552

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I

merely two concentric clutch springs were

" Hammertight " Spanner M 1239E

fitted, the centre nut having a round flange with four peg holes spaced as in end cap. For these earlier units peg spanner ST.9362 can be

After removal of clutch plates, the hexagon clutch centre nut is unscrewed, anti-clockwise,

Page 8

and to prevent clutch shaft turning use clutch sleeve locking plate ST.2551-C/1.

nut has been removed from stud, the chain. case should be eased off the high gear pinion extension, taking care not to damage the oil seal.

ST 2551-C/1

Removal of centre nut allows clutch to be completely dismantled with the exception of sprocket, rollers and roller track; these parts will come away with the primary chain and engine sprocket. If difficulty is experienced in removing engine sprocket a puller having two or three claws can be used such as ST.2587D.

Final Drive Locking Plate ST 2551C/2

Fig. 5

EMOVAL OF FINAL DRIVE SPROCKET

Sprocket Extractor ST 2587D

After removal of sprockets and primary chain, the roller track, which locates against a shoulder on clutch shaft, can be withdrawn.

The clutch sprocket runs on 24—*" x steel rollery; on earlier units 24- 136-' dia. balls were fitted.

REMOVAL OF INNER CHAINCASE The inner chaincase is held in position at the rear by a r dia. stud, which passes through a hole in lug on top of gearbox shell. When

Having removed primary drive and chaincase, the final drive sprocket is now exposed.

If it is required to change the sprocket, and the unit has not been removed from the frame, the rear wheel driving chain should not be removed until the hexagon locknut has been slackened. Set rear brake in the " ON " position, and, before applying a box spanner to locknut, remove lockscrew and spring washer. Turn locknut anti-clockwise to unscrew. Behind locknut is a dished washer; renew this washer each time the sprocket locknut is disturbed.

Alternatively, if engine is in cradle, the sprocket can be held by using a length of chain in conjunction with the cradle, already described. The chain is attached to a link anchored to the cradle as shown in Fig. 11.

The chain with link is available against Ref. ST.2551C/2. When releasing hexagon locknut the chain goes over and then under sprocket. The sprocket is located on the splined end of high gear pinion and can now be withdrawn, leaving distance piece in position inside oil seal.

Page 9

RIGHT-HAND COVER AND CONTACT BREAKER ASSEMBLY Remove three screws and take off contact breaker cover. Detach ignition coil/contact breaker lead by removing nut from the point bracket pin. Removal of the right-hand cover is facilitated if the kicicstart and gearchange levers are removed as follows:— Slacken off clamp bolts. Note position of lever, before removal, so that it can be replaced in correct position. Pull lever from kicicstart spindle, which will also release the return spring and spring cover. The gearchange lever can also be easily removed from the operating spindle.

ture plate, followed by the four slotted screws which secure armature plate to right-hand crankcase, using Extractor ST.2534D. A spigot on the armature plate locates in the ball race housing of crankcase, therefore a little force may be necessary to separate the two components.

Fig 12

4011

.

Screw Extractor ST 2534D

Remove two slotted screws in right-hand cover, and hexagon nut behind armature plate, adjacent to the front fixing lug. The righthand cover is located on two hollow dowels in armature plate, and it may be necessary to gently ease cover off dowels. The ignition coil/contact breaker lead terminal end will pass through slot in the contact breaker housing. There is no need to disturb either contact breaker cam, condenser, or contact breaker points.

IGNITION CAM AND FLYWHEEL Using circlip pliers remove cam retaining circlip from end of crankshaft. Withdraw cam from shaft and remove locating key. The flywheel can now be withdrawn from crankshaft by turning, anti-clockwise, with Hammertight Spanner M.1239D, the hexagon centre nut which is imprisoned in flywheel boss. The centre nut, after initial slackening, will tighten again, further turning will extract flywheel from tapered shaft. A robust tubular box spanner and tommy bar can be used, but to avoid damage to hexagon nut do not use an open ended spanner. Do not place flywheel where small particles of metal can be attracted. It is not necessary to place a keeper across the magnets.

REMOVAL OF ARMATURE PLATE First disconnect lighting lead plug from the twin sockets on armature plate. Remove flywheel locating key to avoid damage to oil seal when the armature plate is removed.

Unscrew H.T. terminal and lead from armapage 10

REMOVAL AND DISMANTLING OF GEARBOX All dismantling operations previously described can be Carried out with engine mounted in the cycle frame. It is necessary, however, to remove the unit if the gear box is to be detached, but before doing this it is advisable to drain oil from gearbox. The clutch operating cable must also be disconnected from lever on gearbox.

The gearbox is attached to the crankcase by four studs, three in crankcase, the fourth in gearbox shell. One or more paper washers are fitted between joint faces of crankcase and gearbox. A note should be made of the number of joint washers, so that the same number are re-fitted when gearbox is reassembled. These washers in addition to providing an oil-tight joint for gearbox, also control tension of primary driving chain.

Two dowels in joint face of crankcase ensure correct alignment of assembly and gearbox shell should be tapped with a mallet when withdrawing from fixing studs.

THREE-SPEED BOX After removal of final drive sprocket, kickstart and change speed levers the next component is the end cover. First the clutch lever adjuster is unscrewed and the lever removed.

The end cover is secured to gearbox shell by six nuts and studs and located by two dowels; between joint faces is fitted a paper washer.

When withdrawing end cover light tapping

with a mallet may be necessary until the dowels are cleared, but before complete withdrawal of cover, and in order not to disturb the gear clusters from their working positions, pressure should be applied to end of kickstart shaft. The gear operating assembly is retained in the end cover by a circlip. The selector plunger and two springs will then be free, leaving the plunger box secured to end cover by the cap nut. One clutch operating rod will probably remain in the mainshaft bush, being retained by the rubber sealing washer. The gear operating assembly need not be removed unless replacements are necessary. Now remove gear selector pivot pin by unscrewing anti-clockwise; this will allow selector fork to drop away from sliding gear operator. The mainshaft and layshaft complete with gears can then be withdrawn, leaving the high gear pinion in the ball bearing.

The pressure washer will probably come away with mainshaft, in any case it must be removed until reassembly. In later models the thrust of the mainshaft, when declutching, is taken by 14—*" dia. balls situated in a recess in end of high gear pinion; carefully collect these balls as they can drop out and be lost.

The pressure washer and high gear pinion in earlier models are of different design and not interchangeable.

The high gear pinion is a light press-fit in the ball bearing, and should be carefully tapped out—do not damage rubber oil seal. Between pinion and bearing will be found one or more packing shims, which must be replaced when re-assembling in order to give correct meshing of gear dogs. To remove ball bearing use a • shouldered" drift," the outside diameter being a little smaller than the sprocket distance piece. Locate end of " drift " in distance piece and with gearbox supported at opposite end, tap with a mallet until bearing is clear of housing. Take care not to damage oil seal.

FOUR-SPEED BOX After removing final drive sprocket, kickstart, gear and clutch levers as previously described for the three-speed box, remove end cover. The end cover is secured to gearbox shell by five nuts and studs and located by two dowels. Between joint faces is fitted a paper washer. When withdrawing end cover, light tapping may be necessary until the

dowels are cleared. Before complete withdrawal of cover, and in order not to disturb the gear clusters and cam barrel from their working positions, pressure should be applied at the clutch end of mainshaft until end cover, with gear assemblies etc., is well clear of gearbox. The high gear pinion and ball bearing can be removed from gearbox shell as described for the three speed gearbox. The mainshaft, layshaft, and cam barrel can now be removed from end cover and also the kickstart shaft if this did not come away with layshaft; care must be taken however not to lose any of the 24--A- x -136-" rollers which form the cam barrel bearing in end cover.

GEAR-CHANGE MECHANISM The "positive stop" gear-change mechanism is retained in end cover by a circlip on gear operating spindle and dismantling is not advised as the assembly is specially adjusted for correct operation. If, however, replacements are required, proceed as follows:— Remove circlip, when the complete assembly can be taken from the end cover. Washer will fall free, and sealing ring will remain in end cover. Ratchet spring and operating pawl, complete with spring, can be removed towards splined end of lever. To remove remaining components, lock-washer should be turned down and nut removed. Note order of removal of components, paying particular attention to small shim(s) under washer. The bush in end cover should not be removed unless replacement, due to wear, is necessary.

To dismantle cam barrel proceed as follows: Turn both selector forks on cam barrel to "widest apart" position, which will make ends of split pins accessible. Remove split pins thus releasing sliding gear fork peg, spring and ball from each fork. Forks are now free to be removed from cam barrel. No attempt should be made to remove barrel bearing pin and thrust washer from gearbox shell and there is no need to remove lcickstart ratchet stop or clutch bridge unless replacements are required.

SPEEDOMETER DRIVE THREE AND FOUR SPEED BOXES Where provided, this is fitted on the under side of the gearbox shell and is secured by twopage 11

studs with nuts and washers. A joint washer is fitted between speedometer box and gearbox shell; lubrication by gearbox oil. The large gear meshes with layshaft fixed pinion, alternative gears and spirals being available to provide for correct revolutions per mile of speedometer drive cable. It is not usually necessary to dismantle the drive or to remove it from gearbox. lithe latter is done it is advisable to fit new joint washer in order to prevent loss of lubricating oil.

SPLITTING CRANKCASE ASSEMBLY

The extractor body is located, at the top, on the two cylinder base studs and at the bottom by a bar bolted through the crankcase frame fixing lug. The crankshaft half should come away with the inner ball bearing and spacer.

The spacer is a loose fit on the shaft, but to remove the ball bearing it will be necessary to use an extractor as Ref. No. ST.2350/2B. With extractor use spanner ST.1633/6.

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Having removed primary drive chaincase halves, right-hand cover, magneto and gearbox as already described, the crankcase assembly can now be dismantled. The crankcase halves are held together by five studs with nuts and plain washers at each end. Remove nuts on one side, then push out studs, two of which are a close fit to act as dowels. When all studs are removed, the right-hand, or magneto side crankcase half will come away, leaving roller bearing inner race and rollers in cage in

BODY

Fig. 14

CENTRE SCREW

Roller Race Extractor ST 2350/1A Ball Race Extractor ST 2350/2B

Crankcase Separating Tool ST 2568 position on the crankshaft. The bearing outer race is retained in the crankcase by a circlip, which should be removed only when a replacement bearing is required. The left-hand or drive side of crankshaft runs in two ball bearings, the outer race of outer bearing being retained in crankcase by a circlip. The inner ball bearing locates against crankshaft web, and between the two bearings is a spacer.

The crankshaft assembly is removed from lefthand crankcase half by using extractor Ref. No. ST.2568. page 12

TO REMOVE BEARING

Fig 15

Ball Race Extractor ST 2550

The inner ball bearing is a light push fit in crankcase and should this not come away with crankshaft, the bearing will drop out if the crankcase is heated.

To remove roller bearing inner race with rollers and cage on right-hand driveshaft, use the extractor with split collets ST.2350/1A. To remove the outer ball bearing from the left-hand crankcase, it is necessary first to remove the circlip, using special pliers to engage with the holes in the ears, and the bearing will come out after heating the lefthand crankcase half—if not effective use extractor Ref. ST.2550, in which case it will be necessary to take out oil seal. A new seal will be required when re-assembling the engine.

CONTACT BREAKER ASSEMBLY The contact breaker assembly is mounted on a base plate which should not be disturbed unless replacements are required, otherwise it will be necessary to re-time the ignition when re-building. The base-plate locates on a small dowel and is locked into position by a socket-headed screw. This screw is filled with solder when timing is set at makers. The assembly, comprising point bracket and rocker arm, can be lifted off base-plate after the split pin, washer and screw have been removed.

The condenser is housed behind the contact breaker recess at the front end of the righthand cover and need not be disturbed unless a replacement is required.

page 13

RE-BUILDING TIIE UNITS It is assumed that, after dismantling, all components including oil seals and sealing rings have been thoroughly cleaned, examined and replacements made available where necessary. Do not fit new oil seals until they are mentioned in the re-building sequence of operations. Undamaged seals need not be disturbed but special care must be taken when fitting components which pass through, or come into contact with, the sealing lip.

The best method of cleaning metal components is by pressure wash using white spirit, the parts being immediately dried by compressed air. For components of the electrical ignition and lighting systems use Carbon Tetra-chloride (C.T.C.), or if not available, use white spirit. Dry off as for metal components.

All moving parts of engine and gearbox should be liberally oiled when re-assembling, using clean engine oil. All oil seals should be well lubricated with engine oil before fitting.

DRIVE-SHAFT AND CRANKCASE ASSEMBLY Assuming drive-shafts with connecting rod, have already been assembled the next operation is to place the inner ball bearing and bearing spacer on the left-hand drive-shaft, then the roller bearing inner race on righthand driving shaft. Use a fixture made from a piece of steel channel.

Heat crankcase halves to 120°C if facilities are available; otherwise immerse in boiling water drying thoroughly before fitting bearings, etc. Drop outer ball bearing into housing of left-hand crankcase and fit retaining circlip.

Whilst crankcase is still hot place left-hand side of drive-shaft assembly into crankcase, ensuring that The spacer goes fully home against the ball bearing. Fit circlip and outer roller race in right-hand crankcase. Allow both cases to cool before attempting further assembly.

Fig 16

SERVICING CRANKSHAFT ASSEMBLY Apart from renewal of small end bush, it is recommended that the assembly is returned to the factory for replacement under the Service Exchange Scheme.

PRESSURE BUSH

OIL SEAL

Where full facilities do exist for dismantling, re-assembling and alignment of these assemblies, the following data should be noted:— Crankpin and connecting rod .001" oversize are necessary when original driveshafts are re-used.

Standard size crankpin and connecting rod should be used only with new driveshafts.

Side clearance between connecting rod big end and crank web .0051.009" total.

Press in expander plugs before checking big-end side play or alignment. Align assembly between centres—maximum eccentricity shown on dial-gauge, measured next to balance weights, should not exceed .001". page 14

Oil Seal Assembly Tool ST 2573B Next fit crankcase halves together. For ease of assembly, place right-hand crankcase on a level plate with joint face upwards, a hole

being provided in the plate through which the right-hand shaft-end can pass. Smear joint faces of crankcase halves with Secotine then place the shaft assembly with left-hand case vertically above the right-hand case and lower into position. With one nut and washer already fitted on each of the five studs push them into position and turn crankcase assembly over until drive-shafts are horizontal then fit remaining five plain washers and nuts on other end of studs and tighten securely in diagonal rotation.

The shaft assembly should now be free to revolve easily when rotating by means of the connecting rod. If any stiffness give a few light taps with a mallet at each end of shaft assembly in order to centralise the left-hand ball bearing. Fit new drive side (left-hand) oil seal if necessary, using Tool ST.2573B Fig. 16.

GEARBOX THREE SPEED -

First fit high-gear pinion ball bearing; this goes to the bottom of the housing, and if the gearbox shell is pre-heated as described for crankcase halves, the bearing will drop into position, making the use of a press or drift unnecessary. Place bearing sealing washer, and any shims originally fitted, on to the high

ESSURE JSH

IL SEAL Fig 17

,/.---...---------=--, ...-->

1

GUIDE SLEEVE PROTECTION SLEEVE

Ai

,......1 ■ cz=::

Oil Seal Assembly Tool ST 2626

gear pinion. Where balls are fitted in highgear pinion, these should be retained in position by packing in grease before pinion is pushed into ball bearing; slight pressure might be required to press in and care should be taken to ensure that it goes fully home.

Fit oil seal with the open side towards high gear pinion using tool ST.2626 followed by the spacer, Fig. 17.

The final drive sprocket can then be fitted, followed by the dished washer and nut. It is suggested that a dished washer is fitted under the locknut, although this component was not originally specified. No attempt should be made at this stage to fully tighten the locknut —this should be done using a torque spanner set at 1000 lbs./ins. after bolting the gearbox to the crankcase, and use can be made of the cradle and locking chain, Tool Reference ST.2551C/2. The gear cluster with mainshaft and layshaft should now be assembled with the sliding gear operator and the mainshaft pressure washer in their correct positions.

Make sure that the pressure washer fits over splines on mainshaft. The complete gear cluster should now be placed into gearbox, the mainshaft entering the high gear pinion and the layshaft into its bush already fitted in the gearbox shell. Next place gearchange selector fork in position, ensuring that fork ends engage with pegs on sides of sliding gear operator. Replace gear selector fork pivot pin, making sure that it is fully screwed home and securely tightened. Now place kicicstart shaft complete with pawl, plunger and spring in position against kickstart pinion. It will be necessary to depress the pawl so that the assembly can be pushed home into the pinion. The kickstart shaft should be turned so that the pawl is away from the return stop in end cover, otherwise some difficulty may be experienced in fitting gearbox end cover. Now fit the gearchange operating spindle assembly into its bush in the end cover, followed by the sealing ring, washer and circlip. The plunger box should also be placed into position and the nut screwed up lightly to locate the box.

At this stage fit plunger and short spring.

Fit new push rod sealing washer and replace one push-rod; all rods are *" dia. in earlier gearboxes, but the push-rod fitted at the clutch lever end of mainshaft is I" dia. in current production models—the hole in the centre of sealing washer should be suitable for the particular diameter of push-rod in use. page 15

Now smear the joint face of the gearbox shell with Secotine and carefully place paper joint washer in position over studs. Apply a thin coat of Secotine to joint face of gearbox end cover, and place in position over fixing studs, making sure that ball joint on gear selector fork engages with fork on gear operator spindle assembly. Lightly tap home the gearbox end cover. Should there be difficulty in bringing the two halves of gearbox together, it is possible that the mainshaft pressure washer has come off the splines, and if this is suspected the end cover must be withdrawn and gearbox dismantled sufficiently for the gear cluster to be withdrawn and pressure washer replaced on splines. A check should also be made to ensure that kickstart shaft is not fouling its stop. When end cover is fully home on gearbox shell the plain washers and i" nuts should be replaced and firmly tightened in diagonal rotation.

assembly. Re-assembly of kickstart lever with return spring and cover is best left until the right-hand cover of engine has been replaced. *FOUR-SPEED GEARBOX

The operation of fitting ball bearing and high gear pinion together with packing shim, bearing spacer, oil seal, final drive sprocket, dished washer and locknut is the same as previously described for three-speed gearbox.

All other components are first assembled on to gearbox end cover before being coupled to gearbox shell. First assemble sliding gear forks on to cam barrel placing in position gear selector fork pegs followed by the - 136-" dia. balls, springs and retaining split pins. The split pins should be inserted from the outer end of forks and the end of each split pin turned flat and well clear of the portion of the fork which engages with the sliding gears.

Remove plunger box cap nut and place the Next build up gear selector mechanism on to longer plunger spring into position. Replace operating spinale, making sure that packing cap nut and tighten securely. The gears should shim(s) is replaced to allow gear operating now rotate freely by turning either the final quadrant to revolve freely on spindle without drive sprocket or mainshaft, and, using the end-float. Now place gear operating pawl, gear-change lever, select each gear in turn to with return spring, in position on spindle make sure there is no stiffness in the gears. followed by the pawl spring. The complete There should be a small amount of end float, assembly should now be placed into position minimum .003", maximum .035", in mainin its bush in gearbox end cover making sure shaft. It is most important to check that that the ratchet spring engages with the spring dogs of mainshaft sliding pinion fully engage stop and that the slot in gear operating spindle with dogs of high gear pinion when in top plate engages with the stop peg. Light gear. If this is not the case it will be necessary pressure will be necessary to push spindle to fit an additional shim behind the high gear home into bush. Next fit spindle sealing ring 1)inion, when a careful check must be made followed by the seal retaining washer and on the mainshaft end float to ensure that there circlip. The assembly is now retained in the is sufficient clearance. The sliding pinion cover. There should be .005" side clearance should not be hard against the high gear between end of gear operating pawl return pinion when in top gear, neither should the spring and stop; if there is too much, or no forks of the gear-change selector hold the clearance of the spring ends on the stop, sliding gear operator tight against the mainerratic gear changing will result. Now ensure shaft and layshaft sliding pinions. If no new that cam barrel bearing and thrust washers, components have been necessary all clearalso kickstart ratchet stop, stud, sealing ring ances etc., should be in order provided that no and push rod sealing washer are in position. wear has taken place on the various thrust Next insert one of the - A- " push rods or the faces. Replace gearbox drain plug, filler plug r push rod, depending upon the type fitted; and dip stick together with their respective the sealing ring must be a good fit on the push washers. If oil level screw and washer have rod. Next assemble gear clusters, with mainbeen removed these should now be replaced. shaft and layshaft in their relative positions, Do not replace clutch bridge and clutch lever on gear selector forks, making sure that the at this stage. two thrust washers are correctly located on splines. Then place into position the kickstart ratchet and shaft with spring. For ease Replace kickstart shaft sealing ring. Gearof assembly gears should be in neutral and it box is now ready for fitting to the crankcase *See page 5 for later pattern "Gear Change Control" page 16

may be necessary first to turn the selectors on cam barrel to give this position. A mark ground at the pinion end must coincide with a punch mark opposite one of the teeth of gear operating quadrant—See Fig. 18 below.

plug/dipstick. Gearbox is now ready for re-assembly to crankcase.

ASSEMBLY OF GEARBOX TO CRANKCASE

Fig

18

I MARKS MUST BE IN LINE ' WHEN MESHED

gtE9

The complete gear cluster, together with cam barrel can now be offered up to gearbox end cover making sure that the gear timing marks are set correctly. The joint face of the gearbox shell should now be lightly coated with Secotine and the paper joint washer placed in position over studs. Lightly coat the joint face of end cover which, complete with gears etc., can now be fitted to gearbox shell, first making sure that the two pressure washers are positioned on their respective splines and kickstart ratchet is not fouling the ratchet stop. The mainshaft will enter the high gear pinion, the layshaft its bush in the gearbox shell, and the cam barrel will locate on the bearing pin. If all components are in their correct positions the gearbox end covers will go fully home, the only pressure needed being to compress the kickstart ratchet spring and overcome the slight resistance when end cover engages with two locating dowels. Now fit the five I" plain washers and nuts tightening in diagonal rotation. It may be necessary to turn the kick-start shaft clockwise to disengage kickstart ratchet, after which a check should be made to ensure that the gears turn freely in neutral position and that all gear positions can be correctly selected. Mainshaft end float should be between limits of .0261.002. Fit the sealing ring on the kicicstart shaft. Do not replace clutch bridge should this have been removed, or lever, at this stage. The lcickstart lever return spring, cap, etc., should not be replaced until after the right-hand cover has been fitted. Fit oil drain and filler

Assuming that the three long gearbox fixing studs are screwed into the crankcase halves, the short stud into gearbox shell, and the two dowels also are in position, fit new joint washers of the same quantity as originally used and place gearbox assembly into position.

After threading one plain washer on each of the four studs, tighten the nuts in diagonal rotation. The paper joint washers provide means of adjustment of primary chain tension, therefore it is now necessary to fit, loosely, engine sprocket and clutch chainwheel assembly, the chain being in engagement. The clutch chainwheel must be mounted on its bearing track with balls or rollers, as the case may be, in position on the gearbox mainshaft. Holding the clutch chainwheel squarely against the bearing track, turn it until chain is at its tightest point, there should then be i" approx. total up-and-down movement of chain at a point midway between the two sprockets. If the movement is less, one or more joint washers should be removed, but if movement is greater, additional washers must be fitted.

The paper washer(s) also act as an oil seal for gearbox, therefore at least one washer must always be fitted, maximum permissible being four. If, with four washers, the chain is still too slack, the chain or sprocket teeth are probably badly worn. Sprockets, chain, etc., must now be removed prior to fitting inner chaincase. If the final drive sprocket locknut was not tightened at the time of gearbox assembly, this should be done before fitting inner chaincase. The crankcase with gearbox attached should now be mounted in the cradle and the sprocket locknut tightened turning clockwise with torque spanner and suitable socket, using chain and link ST.2551-C/2.

The chain must be fitted under and then over the sprocket, clockwise, when tightening the locknut. Next fit locking screw, with spring washer, in the most suitable of the two tapped holes provided in face of sprocket. The engine can be left in the cradle for remainder of assembly. page 17

ASSEMBLY OF INNER CHAINCASE, PRIMARY DRIVE, CLUTCH AND CLUTCH OPERATING PUSH RODS First of all, make sure that the large chaincase fixing stud is tight in crankcase. Place joint washer in position over stud and crankcase spigot. Fit new oil seal if necessary; the open side must be towards inside of case.

In earlier models a felt sealing ring was fitted, retained in position by a dished plate and four copper rivets which have to be removed if a new felt washer is required. Place inner chaincase over the fixing stud, and guide oil seal (or felt gland) carefully over the extension of high gear pinion. The rear stud locates in a lug on gearbox shell, and the 1" nut with plain washer can then be securely tightened.

As the inner chaincase is positioned by the gland on the pinion extension, the clearance hole, for engine sprocket, may not necessarily be concentric with the crankcase spigot; this clearance is necessary to allow for variations in sprocket centre dimension, determined by the number of gearbox/crankcase joint washers mentioned previously. The engine sprocket and clutch chainwheel alignment must now be checked by fitting engine sprocket in position on crankshaft and the clutch chainwheel assembly, mounted on bearing track with balls or rollers in position, located against the shoulder on gearbox mainshaft. Holding clutch chainwheel squarely against the bearing track, place a straight-edge against the face of the engine sprocket and check that it lines-up with the teeth on clutch chainwheel. If it is found that engine sprocket and clutch chainwheel are not in line fit one or more shims behind engine sprocket. Next, remove engine sprocket and clutch chainwheel assembly etc., and fit engine sprocket key, taking care not to damage the oil seal. Next, place the primary chain round the two sprockets and fit them to their respective shafts, making sure that the key locates correctly in keyway of engine sprocket. Apply a liberal coat of graphite grease to balls or rollers of clutch chainwheel bearing, followed by the copper shim, and apply graphite grease to the outside of the shim. Fit clutch backplate over splines on gearbox mainshaft, followed by the clutch hub, sliding sleeve and the two coil springs, or the nine springs, depending upon the type fitted. Grease springs before fitting. If the clutch is of the two spring type, screw clutch page

18

centre nut on end of mainshaft. With locking tool ST.2551-C/1 in position on the clutch sliding sleeve, use peg spanner ST.9362C, to tighten clutch centre nut. If clutch is of the nine spring type, fit spring retaining washer followed by the centre nut. A short length of A." diameter rod must be inserted through the hole in the washer and into the centre of one of the clutch springs before the centre nut is tightened; if this locating pin is not used the clutch springs are likely to be damaged by the washer turning as the nut is tightened. Next, fit the four clutch driving plates and three intermediate plates followed by the pressure plate. Next, fit engine sprocket spring washer and locking nut and securely tighten using sprocket locking tool ST.1380. Now insert the two remaining push rods into the mainshaft. In gearboxes having three IV dia. push rods, all rods are of equal length, but in gearboxes having two 11-" dia. rods and one '+ dia. rod, the two *" rods are of unequal length but the order in which they are inserted into the mainshaft is not important.

Next, fit clutch cap nut and tighten down using peg spanner ST.9362C or ST.2552.

As the cap nut is tightened the springs will be compressed by clutch sliding sleeve movement towards cap nut. In cases where shims were fitted between the cap nut and sliding sleeve, care must be taken to replace them when re-building. The number of shims required is determined by the dimension between the top of the threaded portion of the sliding sleeve and the outer face of the pressure plate (see table below). Shims are used only in later engines where the cap nut having a f" recess and sliding sleeve with a threaded portion ir deep is fitted. In earlier engines shims are not required although in cases where there is a tendency for the clutch to slip, the cap nut having the 4° recess can be fitted to increase pressure applied to clutch plates.

Dimension 12." or less fit two *' shims "

or less fit one 71-," shim

44" or less fit one *" shim Greater than i" no shim required.

When measuring, apply pressure to the pressure plate using two fingers, one each side of the sleeve. The clutch push-rod

adjuster with roller insert in the end cap must now be screwed in or out so that the righthand rod projects " from the end of the gearbox shell (see sketch).

Fig. 19 Where new clutch plates with bonded facings are fitted, the dimension should be IT" to allow for bedding down. After tightening adjuster screw locknut, the clutch bridge can be fitted, followed by lever adjusting screw and lever. The end of the clutch lever adjacent to the adjuster and push rod should be liberally greased. Final adjustment of clutch lever cannot be carried out until after the right-hand cover has been placed into position. Check that chaincase oil filler plug and level screw with washers are in position.

On later engines the level plug is positioned towards the front of the inner chaincase.

Do not fit the outer chaincase at this stage as it will be necessary to turn engine over by means of the clutch wheq setting ignition timing.

ASSEMBLY OF PISTON AND CYLINDER Fit one of the circlips into the groove in the piston bush and enter the gudgeon pin into the bush at the other side of the piston. Make sure that the expander ring is behind the lower piston ring and that both compression rings are fitted so that the slots line up with stop pegs in piston ring grooves. Place piston over connecting rod, checking that the word " Front " stamped on crown of piston is towards front of engine, i.e. towards the exhaust port, and line up with small end bush, which is a tight fit in the connecting rod.

The gudgeon pin should now be pushed fully home in piston, passing through the small end bush and into the piston bush on the opposite

side. Make sure that the gudgeon pin comes into contact with the circlip already fitted and then fit second circlip. Be sure that both circlips are firmly located in grooves as severe damage can result from a circlip coming out whilst engine is running. Fit a new cylinder base washer over the four studs of crankcase assembly, line up piston rings with stop pegs and apply a liberal coating of oil to outside of piston. Steady piston with one hand and at the same time compress piston rings with the thumb and forefinger, lowering cylinder into postion. Do not twist cylinder around piston when re-fitting, otherwise ends of piston rings may catch in the ports resulting in broken or damaged rings. Fit the four spring washers and nuts, tightening down in in diagonal rotation. Rotate engine by turning clutch assembly to ensure that piston moves smoothly up and down cylinder bore. Do not fit cylinder gasket or cylinder head at this stage.

REFITTING ARMATURE PLATE, FLYWHEEL AND CONTACT BREAKER ASSEMBLY The armature plate assembly is attached to the right-hand crankcase by four countersunk headed screws. A spigot on the armature plate locates it in the bearing housing and also serves to position the roller bearing.

Fitted into armature plate is the right-hand crankcase oil seal; this should be renewed if necessary before fitting armature plate. Joint faces of crankcase and armature plate should be well coated with Secotine and plate fitted into position on crankcase, making sure that the twin lighting lead and the L.T. lead are not trapped at any point. Fit the four countersunk headed screws and tighten in diagonal rotation. It is most important that these screws are very securely fastened as the plate carries the full weight of the right-hand cover.

To lock the screws a small amount of metal should be punched into the slot of the screw.

Next fit flywheel on to shaft, ensuring that the key remains in position and engages with keyway in flywheel boss. The flywheel centrenut must then be securely tightened using a torque wrench loaded to 750 in./lbs. Hold flywheel by means of a strap wrench.

Now fit ignition timing cam key, followed by the cam. The cam should be a tight push fit on page 19

shaft; if too loose it can be made tighter by squeezing very gently in a vice. Next fit the cam retaining circlip. The right-hand cover is now replaced, but make sure that the condenser is in position and its clip and screw are secure. The cover is held in position by two countersunk headed screws and one stud, with plain washer and nut, the stud passing through the armature plate at the front end.

When placing right-hand cover in position make sure that the L.T. lead is passed through the slot at the rear of contact breaker housing, ready for connecting to contact breaker assembly. Gently tap right-hand cover into position on hollow dowels in armature plate, fit the two screws, plain washer, and nut in position and securely tighten. The cam lubricating pad should be soaked in molten high melting point grease and positioned so that it contacts the cam at the point of maximum lift. Failure to do this will result in rapid wear on fibre heel of rocker arm and possibly a high pitched squeal when the engine is running. If the contact breaker base plate has been disturbed this should be repositioned on the pivot dowel and the fixing screw with washer placed in position. Do not lock up this screw until the ignition has been re-timed. Next re-assemble the various components to the contact breaker point bracket following the order shown in Fig. 13,9E book; the point bracket should be positioned between the fibre bush and fibre washer. The terminal of the L.T. lead should be between fibre washer and shakeproof washer. Do not over-tighten nut on point bracket pin, otherwise damage to insulating bush may result.

Next place point bracket over rocker pivot pin and fit the point bracket fixing screw together with insulating and plain brass washers.

Place rocker arm in position on pivot pin, making sure that the connecting strip locates on the raised pip on back of rocker arm. Then fit rocker arm spring which should locate at one end on the point bracket pin and at the other on the raised pip of rocker arm. A light grease should be used to lubricate rocker arm pivot and rocker arm should be quite free on pivot pin. Now fit rocker arm retaining washer and split pin. The washer must be just free to rotate when the split pin is fitted, otherwise sluggish movement of the rocker arm may result. Only one washer is fitted, but washers are available in four thicknesses, so that all end float of rocker arm can be eliminated by selecting washers of required thickness.

Page 20

RE-SETTING THE CONTACT BREAKER AND IGNITION TIMING Contact breaker assembly is shown in Fig. 20 Turn crankshaft until the rocker arm is fully raised and if necessary loosen screw " E " and adjust point bracket " A " to give a point gap of .0121.015". Tighten screw " E " and rotate crankshaft clockwise until breaker points commence to open. The piston should then be before top dead centre (top of stroke). If piston position differs from this figure, the base plate should be swung to left or right to advance or retard the timing as required and contact point gap re-set if necessary. The base plate is secured by an

a"

A

Fig. 20

raemna.

Contact Breaker Assembly

Allen screw "D," the head of which is filled with solder when the timing is originally set at the makers. It will be necessary to remove this solder before the screw can be released.

Securely tighten screws "D and " E " when correct adjustment has been obtained. A felt oiling pad " C " is provided for the contact breaker cam "B." The pad should be removed periodically and soaked in molten high melting point grease; wipe off surplus grease before re-fitting. Replace the contact breaker cover and the three securing screws.

Re-fit H.T. lead making sure that the felt washer is in position on pick-up terminal before screwing terminal into armature plate.

RE-FITTING THE KICKSTART LEVER The kicicstart lever is located on the shaft by splines and is clamped by a nut and bolt

passing through end of lever. The method of fitting the kickstart lever to the three-speed and four-speed gearboxes is similar, therefore the following details apply to both models, except where otherwise stated.

Rotate engine by means of kickstart lever, ensuring that the lever returns freely and kicksta,rt ratchet fully disengages. This can be checked by turning the clutch assembly by hand in the normal direction of rotation.

The kickstart return spring should be liberally coated with grease and placed in position over kickstart boss with short end of spring located in the second hole from top in the gearbox end cover. Next fit return spring cap and fully turn kickstart shaft clockwise.

Next pass a piece of strong cord over the end of the spring protruding through the spring cap and pull the spring round anti-clockwise until the end of the spring is vertically above the kickstart shaft. Now place the kickstart lever over the splines, again check that the kickstart shaft is fully turned clockwise, and if necessary, adjust position of lever on spline so that it is in its original, almost upright, position. Push lever fully home on spline ensuring that the long end of the spring enters the hole in back of kicicstart lever, and fit the clamping bolt. It may be necessary to turn the kickstart lever through 180 in order to fit the bolt owing to the proximity of the righthand cover. Where the lever is fitted to the four-speed gearbox it is essential that the domed washer is placed into position over the kickstart lever boss and that the screw is tightened into the centre of the kickstart shaft.

This ensures that kickstart lever boss is fully home on shaft, otherwise the ratchet mechanism may not fully disengage. The lever clamping bolt can now be fully tightened.

RE-FTITING THE OUTER CHAINCASE, CYLINDER HEAD AND RELEASE VALVE (If Fitted) Coat the joint face of the inner chaincase with Secotine and place joint washer in position locating it at the rear over the small dowel.

Next coat the joint face of the outer chaincase with Secotine and place the chaincase over fixing stud making sure that it locates correctly on dowel. Now securely tighten chaincase fixing nut. It may be noticed that the front end of the inner chaincase moves toward the crankcase, but this condition is quite normal as the tightening of the nut secures both the inner and outer chaincases at the front end.

If the joint washer protrudes over edge of chaincases this can be trimmed off, using a sharp knife. Next fit cylinder head gasket followed by cylinder head, its four fixing bolts and plain washers under bolt heads. Tighten bolts in diagonal rotation and pull fully home using a torque wrench loaded to 390 in./lbs.

Replace release valve, if one is fitted, on drive side (chaincase side) of the cylinder head, making sure that the small copper joint washer is fitted. Next place sparking plug into position to prevent any foreign matter being introduced into the cylinder through the spark plug hole.

ik;.•

page 21

Mark 9E/LF, Mark 2L/LF, and Mark 31C/LF UNITS WITH FAN and COWL and KICKSTARTER These are the units now standardised by a large number of scooter manufacturers. They are basically similar to those fitted to motor cycles, but have in addition a built-in fan and cowling on the drive side as standard equipment. The technical data is as for the motor cycle type of engine.

These models are also in production incorporating the SIBA " DYNASTART " unit, but these are dealt with under a separate heading.

DISMANTLING The instructions already given for the motor cycle units apply, with the exception of the paragraphs dealing with removal of cylinder head and cylinder, and removal of outer chaincase. Before the cylinder head bolts can be unscrewed the cowl surrounding the cylinder and head must be removed. This is secured to the outer chaincase by two cheesehead screws and to the stud in top of cylinder.

To gain access to the clutch and primary drive components the cowl bottom/outer chaincase has to be removed, but before this can be done the fan has to be withdrawn from the end of driveshaft. The fan is located by a woodruffe key and secured by two nuts, the outer one acting as a locknut. Between the fan centre and the engine sprocket is a distance piece which runs in an oil seal, carried in a housing secured to the wall dividing the outer chaincase from the fan cowling. The fan can be pulled off the driveshaft using the same extractor, ST.2587D, as for the engine sprocket, using two r dia, x 26 TPI screws instead of -156-" dia. Whit thread.

The crankshaft assembly is, apart from the left-hand, or drive-side shaft, as for the motor cycle units with Villiers flywheel magneto.

The left-hand shaft is, of course, a little longer to accommodate the fan.

page 22

The Tool ST.2573B normally used for fitting the oil seal in the left-hand crankcase half, is not suitable. A tool, having a longer pilot and body is available, Ref. ST.177613.

Fig. 25 Off Seal Assembly Tool ST.17768

Mark 9E/SLF, 2L/SLF, 31C/SLF UNITS with FAN and COWL and SIBA " DYNASTART "

These units are basically motor cycle engines with either three or four-speed gearbox, fan and cowl on drive side, and the SIBA " DYNASTART "unit on the righthand side in place of the usual Villiers magneto.

Where details with regard to dismantling and re-building differ from the motor cycle units, these are covered by separate paragraphs. The technical data is generally as for the motor cycle engines excepting that an additional roller bearing (Type R.320) is fitted on the starter side driveshaft.

CYLINDER HEAD AND CYLINDER

As already described for the motor cycle unit, but it will be necessary to first remove the top portion of cowl.

REMOVAL OF OUTER CHAINCASE

As for the motor cycle unit, but it will be necessary first to remove the fan and cowling as already described.

RIGHT-HAND COVER AND CONTACT BREAKER ASSEMBLY The contact breaker is exposed after removal of the cover plate secured by two screws. A paper washer is fitted between the joint faces. Removal of the right-hand cover does not call for dismantling of the contact' breaker assembly, but it is necessary to detach the leads connected to the terminals A. D. & DF of the switch box assembly when dealing with the unit having the uni-directional SIBA starter. In the case of the reversible SIBA starter it is necessary to disconnect the leads BI, B2 and HE from the solenoid and leads DF and A from the switch box. The black and red leads from the reversible contact breaker to the solenoid need not be removed.

The right-hand cover is attached to the stator housing by two countersunk headed screws and one nut fitted to a i" dia. stud in the back and at the front end of the housing.

The cover is located by two hollow dowels.

To facilitate removal of right-hand cover, it is

advisable to remove the gear control lever, and also the kickstart lever where fitted.

IGNITION CAM AND ROTOR

The cam fits into a recess in the rotor and is secured by two screws. A slot in cam flange ensures correct positioning when replacing. The rotor is keyed to the tapered driveshaft, and is secured by a hexagon flanged nut. For removal of nut use a tubular box spanner such as the " Britool " No. 5120 or alternatively the torque spanner which is necessary when refitting the rotor.

To pull the rotor off driveshaft use an extractor, obtainable from the Villiers Service Dept., Ref. No. SST.1565D. The boss of the rotor is internally screwed to take the extractor body, and turning the centre screw clockwise will pull the rotor off the driveshaft.

Fig. 21

41°11 I "Al

1

41

Rotor Extractor SST.1565D

Whilst the rotor is being withdrawn and also when re-fitting the centre nut, it is necessary to prevent the rotor turning. This is done by using a strap type wrench such as the Britool Ref. No. 3,001 on the rotor page 23

where the cooling fan is fitted on the left-hand or drive-side of unit. For units having the fan on the right-hand side, the cowling prevents a strap wrench being used and a suitable tool is available under Ref, No. ST.1687A. This tool is screwed to the face of the rotor, being located by two dowels, and secured by two set screws. Having removed the rotor, blow out any carbon dust from inside and place the rotor on a clean surface with the inside facing upwards. Be careful not to damage the windings. The stator is fixed to the crankcase by three Allen socketheaded screws with shakeproof washers but before undoing these remove the woodruffe key from the crankshaft, otherwise the oil seal in stator will be damaged.

same time. This is secured to crankcase by four countersunk headed screws. Use tool Ref. ST.2534/D and withdraw the stator and stator housing together without displacing the cables in the grommet.

The procedure for dismantling crankcase is the same as for the standard motor cycle unit.

There are, however, two roller bearings with spacer between fitted on the starter side driveshaft. The outer roller bearing inner race and spacer can be removed by using an extractor Ref. ST.2574/B. The claws of extractor are located in the slots provided in the spacer, and adjacent to the roller bearing inner race. For the remaining roller bearing inner race use extractor Ref. ST.2350/1A.

Fig. 22 DOWEL TO LOCATE TOOL ON FACE OF ROTOR

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--

SCREW INTO TAPPED HOLE IN FACE OF DYNASTART ROTOR

Rotor Holding Tool ST.1687A

Fig. 23 Extractor ST.2574B

The stator should only be removed when it is necessary to split the crankcase. The stator housing need not be detached at the

REBUILDING THE UNIT The procedure is similar to that for the motor cycle unit, but differs in respect of the fitting of the SIBA starter and the cooling fan and cowling.

DRIVESHAFT AND CRANKCASE ASSEMBLY As for the Mk. 9E, except that there are two roller bearing outer races and three circlips to be fitted in the right-hand crankcase half.

THREE AND FOUR-SPEED GEARBOXES Normally Mk. 9E units incorporating the SI-13A starter are not provided with the gage 24

kickstarter in addition, but an exception is the unit fitted in the Bond Minicar. Therefore the paragraphs dealing with the standard Mk. 9E gearboxes will apply in the case of the Bond Minicar, but normally where the SIBA starter is fitted the kickstarter mechanism is omitted and an alternative gearbox end cover is fitted.

REFITTING STATOR HOUSING " SIBA " STARTER AND CONTACT BREAKER ASSEMBLY Before attempting to replace the stator housing and the rotor, which because of the connecting cables must be treated as a unit,

the carbon brushes must be examined for wear and all traces of carbon dust removed by means of a soft brush or compressed air.

A seal is fitted in the stator to prevent escape of oil from the engine crankcase. If any oil is found on the brush gear or stator windings this must be removed and the oil seal replaced.

Brushes should be replaced when worn to the shoulder.

When checking the brushes see they slide quite freely in their holders, and the leads lie close to the stator coils to prevent contact with the flywheel. Each brush is complete with spring and pigtail, but adjacent pairs are not interchangeable, nor are diagonally opposite pairs on uni-directional units. When changing brushes, remove only the screw securing the pigtail, so as not to disturb the brush holder.

In reversible units all brush holders are insulated from the stator frame and holder securing screws, and care must be taken to ensure that the insulation is replaced in the original order and in good condition, as faulty insulation here can result in serious damage. Red paint indicates insulated brushes.

On insulated holders, the brush pigtail tag has a large hole to pass over the insulating bush. The uni-directional stators have two brush holders which are not insulated and here the brush pigtail tags are just normal clearance on the securing screws.

After a long period of iervice the commutator will probably require skimming to correct for wear. This is a job which should be entrusted to qualified electrical repairers or sent to Villiers Service Dept.

Clean mating faces of the crankcase and stator housing and coat the end face of crankcase centre boss and the mating face in the bottom of the stator with " Wellseal " jointing compound to prevent an oil leak from crankcase.

Next fit the stator housing on crankcase spigot and secure with the four countersunk headed screws having previously coated the heads with Secotine. After tightening, peen the aluminium into the head slots with a centre punch. Tightening and locking these

four screws is most important as entire weight of right-hand cover with various components is carried by the stator housing. Now fit the stator, taking care not to damage the oil seal on the shaft keyway. Secure with the three socket-headed screws and shakeproof washers.

Next fit rotor locating key making sure that this is a good fit in keyway.

Again check that all brush pigtail connections lie against stator windings and that brushes are correctly positioned and free to slide in their holders.

Rotor can now be fitted on crankshaft making sure that the key locates correctly.

Next fit rotor securing nut and tighten with torque spanner, Britool EVT.1700-R, loaded to 650 lbs./ins. It will be necessary to hold the rotor flywheel by a strap type wrench or alternatively the tool Ref. ST.1687A. Turn rotor by hand after tightening fixing nut, to ensure that rotor runs true and does not foul stator.

Replace ignition cam, checking that the slot locates with indent in hub of rotor. Secure cam by two fixing screws with spring washer under head of screw.

Right-hand cover can now be fitted, making sure that the lead/s from contact breaker/s are in position and well clear of rotor. Cover is held in position by two countersunk headed screws and one stud and nut which passes through stator housing at front end. The cover is located on two hollow dowels in stator housing. On models with four-speed gearbox having an electrical neutral indicator, indicator lead must be attached to indicator contact before right-hand cover is fully home.

POINT SETTING AND IGNITION TIMING The method of resetting ignition timing and adjustment of contact breaker points is identical for both uni-directional and reversing SIBA units. General view of contact breaker assembly for both types are shown in Fig. 24. page 25

The base plate is identical for both types, but only the right-hand contact breaker arm and point bracket is fitted for the uni-direcFig. 24

having the suffix /1 the correct point gap is also .020"/.022", but for reversing engines with the earlier type cam the gap is .014"/.016".

Timing for the reverse direction of rotation is determined by the shape of the cam and cannot he adjusted.

r"

TO REMOVE THE ROCKER ARM FOR POINT CLEANING OR REPLACEMENT

tional unit. Set piston at top dead centre and slacken screw (A) and turn screw (B) which can either widen or narrow the point gap.

Adjust the gap to .020"/.022" and tighten screw (A). This gap applies where the cam flange is marked with /1 following the code letters, i.e. FCDX/1. The ignition timing is correct when the contact breaker points are just breaking and the piston is ir before top dead centre. If necessary rotate baseplate after slackening the two screws (C); moving baseplate clockwise will retard the ignition in the forward direction and vice versa. When baseplate is correctly positioned securely lock baseplate screws and re-check point gap, again with piston at top dead centre. Timing for reverse rotation does not require setting, but will be correct if timing for forward rotation has been correctly carried out.

On uni-directional engines having the earlier type cam with identification letters not

Remove clamping screw (A). Take off the small circlip and thin steel washer from the rocker pivot spindle, and with the aid of a small thin screwdriver lift the white plastic insulating pad out of the point bracket. This needs a little care, but the complete rocker with contact point, spring and cable will lift off its spindle There is another thin steel washer underneath.

It is inadvisable to attempt to unsolder the cable from the rocker tag, and if complete removal is necessary then the cable should be withdrawn from the cover. If the adjustable point requires replacing, whilst the rocker is off, remove the clamp screw, when the point bracket can be lifted away.

The oiling pad should be inspected, and if quite dry allowed to absorb a drop of oil, applied on the lower end. Ensure that it touches the cam.

Lubricate rocker pivot pin and bush, preferably with light grease, when refitting, which is the reverse procedure of that outlined above.

/11:11,s page 26

Mark 9E Competition Gear Unit This is basically the standard motor cycle power unit with either a three or four-speed gearbox, but in order to obtain additional power, the specification varies in several respects from the standard.

Two competition models are available, (1) Sports and (2) Trials. The specifications are alike with the exception that the Sports engine is fitted with the standard magneto flywheel, whereas for the Trials model a heavier flywheel is fitted in order to obtain smoother torque at the lower speed range.

The compression ratio is raised from 7.25: 1 to 8.25: 1 by fitting a cylinder head having a reduced combustion space.

The bore of the cylinder is .0005" larger than standard to eliminate possible piston seizure at full throttle. The big end bearing consists of nine i" dia. x -is" long steel rollers, caged, and the side clearance between con rod and driveshafts is increased to .008"/.012" to ensure adequate lubrication.

A special ignition coil is fitted to the armature plate and a non-standard cam, giving a longer dwell for the closing of contact breaker points is provided in the flywheel assembly.

Gear ratios are as listed on the Technical Data sheet and it is usual to call for the wide ratios for Trials and the standard ratios for Scrambles.

The Villiers Type S.25/2 carburetter is fitted to a non-standard inlet pipe. The type V.1800 air filter has a renewable felt element.

When ordering replacement parts for competition engines, always quote the full number which is stamped on the nameplate attached to engine.

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,1 44 page 27

Mark 9E ENGINE GEAR-UNIT for " HARTS " The majority of KARTS competing in the 197 c.c. class are powered by the Villiers Mark 9E unit, the relevant basic specifications being as follows:—

Specification 076D Basically the standard Mark 9E unit with three-speed gearbox having standard ratios and positive stop gear control mechanism with short control lever instead of the foot lever. The cylinder bore is .002' larger than standard to give increased clearance for the piston skirt.

An ignition cut-out terminal screw is fitted to the right-hand cover. To this terminal is connected a cut-out switch and lead to comply with the regulations governing KART racing.

One of the four cylinder head bolts is replaced by a stud to which is connected a frame steady strap.

The carburetter is a Villiers type S.25/1 in which the usual fuel needle lever is deleted. A specially long fuel needle is fitted together with a non-standard float which bears directly against the needle. Inlet pipe as for the Mark 9E competition unit.

Specification 152D This unit is as Specification 076D, above, except that a four-speed gearbox, with standard ratios, is fitted.

Specification 110D Mark 9E/4 SPORTS MODEL This unit is similar to Specification 152D, but embodies several features to be found in the Mark 9E Competition unit specification. The cylinder bore is .0005' oversize and a high compression cylinder head is fitted. The competition type magneto, inlet pipe and connecting rod assembly are standard equipment.

There are in service Mark 9E units, built to specifications different from above in some respects.

It is, therefore, very important that the full engine number is quoted, when replacement parts are required.

page 28

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