Vespa LX - S 125 - 150 i.e. 3V MY 2012 (EN)

SERVICE STATION MANUAL 677570 EN

MSS Vesp MSS Vespa a LX - S 125 125 - 150 i .e. 3Va 3Vall v o l e (2012)

SERVICE STATION MANUAL

MSS MS S Vesp Vespa a LX - S 125 125 - 150 i .e. 3Va 3Vall v o l e (2012)

The The descr escrip ipttions ions and and imag images es in this public blicat atio ion n are are given iven for illu illust stra rattive ive purp urposes oses only only and and are are not not bind bindin ing g. While the basic characteristics characteristics as described des cribed and illustrated in this this booklet remain remain unchanged, Piaggio P iaggio & C. S.p.A S .p.A.. reserves reserves the right, at any time time and without being required to to update this this publication beforehand, beforehand, to make make any changes to components, components, parts or accessories accessories,, which it considers considers necessary neces sary to improve improve the product or which are required for manufacturing manufacturing or construct construction ion reasons. reasons. Not all versions/models shown in this publication are available in all countries. The availability of each model should be checked at the official PIAGGIO sales network. ©Copyright 2012 - Piaggio & C. S.p.A. All rights reserved. Reproduction of this publication in whole or in part is prohibited. P iaggio iaggio & C. S.p.A. Viale Rinaldo Rinaldo Piag P iaggio gio,, 25 - 5602 56025 5 PONTE PO NTEDER DERA A (PI), (P I), Italy www.piaggio.com

SERVICE SERVICE STATION STA TION MA MANUA NUAL L MSS Vespa LX - S 125 - 150 i.e. 3Valv 3V alvo o l e (2012 (2012)) This This ser service ice stat statio ion n manu anual has been een com compiled iled by Piaggi Piaggio o & C. Spa to be used sed by aut authoris orised ed work orkshop shops s and Piaggio Piaggio trade trade offices. This T his manual manual is addressed address ed to to Piaggio P iaggio service mechanics mechanics who are supposed to have a basic knowledge of mechanics principles and of vehicle mounting techniques and procedures. Any important changes made to the vehicles or to specific mounting operations will be promptly reported by updates to this manual. Nevertheless, no mounting work can be satisfactory if the necessary equipment and tools are unavailable. It is therefore advisable to read the sections of this manual concerning special tools, along with the special tool catalogue.

N.B. P rovides key key information information to make make the procedure easier easier to understand and carry out.

CAUTION Refers to specific procedures to carry out for preventing damages to the vehicle.

WARNING Refers to specific procedures to carry out to prevent injuries to the repairer.

Personal safety Failure to completely observe these instructions will result in serious risk of personal

injury.

Safeguardin Safeguardin g the enviro nment S ections marked wit with h this sym symbol bol indicate the correct use of the vehicle

to prevent damaging the environment.

Vehicle intactness The incomplete or non-observance of these regulations leads to the risk of serious

damage to the vehicle and sometimes even the invalidity of the guarantee.

INDEX OF TOPICS

CHARACTERISTICS

CHAR

TOOLING

TOOL

AINTENA NCE M AINTENANCE

MAIN

TROUBLESHOOTING

TROUBL

ELECTRICAL

ELE SYS

SYSTEM

ENGINE FROM VEHICLE ENGINE

ENG VE ENG

INJECTION

INJEC

SUSPENSIONS

SUSP

B RAKING

SYSTEM

CHASSIS PRE-DELIVERY

BRAK SY SYS S CHAS PRE DE

INDEX OF TOPICS

CHARACTERISTICS

CHAR

MSS Vesp Vesp a LX - S 125 - 150 i.e. 3Valv 3Valvol ole e (2012) (2012)

Characteristics

This This sect sectio ion n descr escrib ibes es the gener eneral al spec specif ific icat atio ion ns of of the vehic ehicle le..

Rules This This sect sectio ion n descr escrib ibes es gener eneral al saf safety ety rules les for for any any main aintenan enance ce oper operat atio ion ns per perfform ormed on the vehic ehicle le..

Safety Sa fety rules r ules - If work can only be done on the vehicle with the engine running, make sure that the premises are well ventilated, using special extractors if necessary; never let the engine run in an enclosed area. Exhaust fumes are toxic. - The battery electrolyte contains sulphuric acid. Protect your eyes, clothes and skin. Sulphuric acid is highly corrosive; in the event of contact with your eyes or skin, rinse thoroughly with abundant water and seek immediate medical attention. - The battery produces hydrogen, a gas that can be highly explosive. Do not smoke and avoid sparks or flames near the battery, especially when charging it. - Fuel is highly flammable and it can be explosive given some conditions. Do not smoke in the working area, and avoid naked flames or sparks. - Clean the brake pads in a well-ventilated area, directing the jet of compressed air in such a way that you do not breathe in the dust produced by the wear of the friction material. Even though the latter contains no asbestos, inhaling dust is harmful.

Maint Ma int enance rules - Use original PIAGGIO spare parts and lubricants recommended by the Manufacturer. Non-original or non-conforming spares may damage the vehicle. - Use only the appropriate tools designed for this vehicle. - Always use new gaskets, sealing rings and split pins upon refitting. - After removal, clean the components using non-flammable or low flash-point solvents. Lubricate all the work surfaces, except tapered couplings, before refitting these parts. - After refitting, make sure that all the components have been installed correctly and work properly. - Use only equipment with metric sizes for removal, service and reassembly operations. Metric bolts, nuts and screws are not interchangeable with coupling members using English measurements. Using unsuitable coupling members and tools may damage the vehicle. - When carrying out maintenance operations on the vehicle that involve the electrical system, make sure the electrical connections have been made properly, particularly the ground and battery connections.

CHAR - 7


Characteristics

Vehicl Ve hicl e ide identif ntif ication

THE FOLLOWING INDICACTIONS REFER TO THE LX VERSION.

VEHICLE IDENTIFICATION VESPA LX Sp ec i f i c at i o n

Des c ./Qu an t i t y

Chassis prefix (125) Engine prefix (125) Chassis prefix (150) Engine prefix (150)

ZAP M68300 - 10000001 M687M 1001 ZAP M68400 - 10000001 M688M 1001

THE FOLLOWING INDICA CTIONS REFER TO THE S VERSION.

VEHICLE IDENTIFICATION VESPA S Sp ec i f i c at i o n


Chassis prefix (125) Engine prefix (125) Chassis prefix (150) Engine prefix (150)

ZAP M68301 - 10000001 M687M 1001 ZAP M68401 - 10000001 M688M 1001

Chassis Chassis number

The The chas chassi sis s number « A » is stamped near the battery compartment. To read read it procee oceed d as follo ollow ws: - lift the saddle; - lift the helmet compartment by removing it.

Engine number

The The eng engine ine number ber «B » is stamped near the rear left shock absorber lower support.

Dimensions and mass

THE FOLLOWING INDICACTIONS REFER TO THE LX VERSION.

CHAR - 8


Characteristics

THE FOLLOWING FOLL OWING INDICACTIONS REFER TO THE S VERSION.

WEIGHTS AND

DIMENSIONS

Sp ec i f i c at i o n


Length Width Maximum height Wheelbase

1770 mm 740 mm 1140 mm 1280 mm

CHAR - 9


Characteristics



Kerb weight Maximum weight allowed

114 kg 300 kg

Engine 125 CM³ ENGINE SPECIFICATIONS Sp ec i f i c at i o n


Typ Type Cubic capacity Bore x stroke Max. power MAX. torque Compression ratio Idle speed Valve clearance Timing ing syst system em

Singl Singlee-cy cyli lind nder er,, 4-st 4-stro roke ke 124 cm³ 52.0 x 58.6 mm 8.5 kW at 8,250 rpm 10.7 Nm at 6,500 rpm (10.5±0.5):1 (1,750±100) rpm intake: 0.08 mm exhaust: 0.08 mm 3 valve alves s (2 (2 int intake, ake, 1 drai draina nag ge). e). sin singl gle e over overhe head ad cam camshaf shaftt chain-driven. Engine lubrication with lobe pump (inside crankcase), chaindriven, with double filter: mesh and paper. F orced-air circulation cooling. Ele Electronic injection with Ø 28 mm throttle body, single injector Unleaded petrol (95 RON) Absorption-type exhaust muffler with catalytic converter. EURO 3

Lubrication Cooling Fue Fuel system F uel Exh Exhaust silencer Emissions compliance

150 CM³ ENGINE SPECIFICATIONS Sp ec i f i c at i o n


Typ Type Cubic capacity Bore x stroke Max. power MAX. torque Compression ratio Idle speed Valve clearance Timing ing syst system em

Singl Singlee-cy cyli lind nder er,, 4-st 4-stro roke ke 155 cm³ 58.0 x 58.6 mm 8.5 kW at 8,250 rpm 12.8 Nm at 6,250 rpm (10.5±0.5):1 (1,750±100) rpm intake: 0.08 mm exhaust: 0.08 mm 3 valve alves s (2 (2 int intake, ake, 1 drai draina nag ge). e). sin singl gle e over overhe head ad cam camshaf shaftt chain-driven. Engine lubrication with lobe pump (inside crankcase), chaindriven, with double filter: mesh and paper. F orced-air circulation cooling. Ele Electronic injection with Ø 28 mm throttle body, single injector Unleaded petrol (95 RON) Absorption-type exhaust muffler with catalytic converter. EURO 3

Lubrication Cooling Fue Fuel system F uel Exh Exhaust silencer Emissions compliance

Transmission TRANSMISSION Sp ec i f i c at i o n


Tran Transm smiss issio ion n

CVT expa expand ndab able le pull pulley ey varia ariattor with ith torqu orque e serv server er,, V-bel V-beltt, self self-ventilating dry automatic centrifugal clutch and transmission housing with forced-circulation air cooling. Gear reduction unit in oil bath.

F inal reduction gear

CHAR - 10


Characteristics

Capacities CAPACITY Sp ec i f i c at i o n


E ngine oil Hub oil F uel tank capacity

1220 cm³(of which 120 cm³in the filtering cartridge) 200 cc (8.2±0.5) l

Electri Electri cal system ELECTRICAL SYSTEM Sp ec i f i c at i o n


E lectric Ignition

Electric starter Electronic inductive discharge ignition, with variable advance and separate HV coil. Three-dimensional map managed by control unit NGK CR8E B 0.7 to 0.8 mm

Ignition advance Spark plug Electrode gap

Frame Frame and suspension s FRAME AND

SUSPENSION



Chassis Fro Front suspension

Stamped plate body with welded structural reinforcements. Sin Single arm with helical spring and single double-acting hydraulic shock absorber. Double-acting shock absorber, ad adjustable to four positions at at preloading.

Rea Rear suspension

Brakes B RAKES Sp ec i f i c at i o n


F ro ront brake

Ø 200-mm disc brake with hydraulic control activated by handlebar right-side lever. Ø 110-mm drum brake with mechanical control activated by handlebar left-side lever.

Rear brake

Wheels and tyres WHEELS AND

TYRES



Wheel rim type F ront wheel rim Rear wheel rim F ront tyre Rear tyre F ront tyre pressure Rear tyre pressure (with passenger)

Light alloy wheel rims. 11'' x 2.50 10'' x 3.00 Tubeless, 110/70 - 11'' 45L Tubeless, 120/70 - 10'' 54L 1.6 bar 2.0 bar (2.3 bar)

CHAR - 11


Characteristics

Tightening Torques CHASSIS ASSEMBL ASSEMBLY Y N am e

To r q u e i n N m

S winging arm - chassis pin Engine-swinging arm bolt S ilent block-swinging arm retaining bolts Centre stand pin

44 to 52 40 to 45 40 to 45 40 to 45

STEERING STEERING ASSEMBLY A SSEMBLY N am e

To r q u e i n N m

Steering upper ring nut Steering lower ring nut Handlebar fixing screw

35 to 40 12 to 14 50 to 55

FRONT BRAKE N am e

To r q u e i n N m

Brake fluid pump-hose fitting Brake fluid pipe-calliper fitting S crew tightening calliper to support Brake disc screw (°) Oil bleed valve (on the calliper) Handlebar pump Brake pump reservoir screw

8 to 12 20 ÷25 20 - 25 5 to 6.5 10 to 12 7 ÷10 15 to 20

(°) Apply LOCTITE 242 threadlock

MUFFLER N am e

To r q u e i n N m

S ilencer heat guard fixing screw Screws fixing silencer to the crankcase Lambda probe tightening on exhaust manifold

4 to 5 24 ÷27 40 to 50

FRONT SUSPENSION N am e

To r q u e i n N m

S hock absorber upper nut F ront wheel axle nut S hock absorber upper bracket bolts Wheel screw Shock absorber lower bolts (°)

20 to 30 75 to 90 20 to 25 20 to 25 20 to 27

(°) Apply LOCTITE 242 threadlock

REAR SUSPENSION N am e

To r q u e i n N m

Rear wheel axle Shock-absorber/chassis nut Lower shock absorber clamp

104 ÷126 20 to 25 40 to 45

FLYWHEEL N am e

To r q u e i n N m

F lywheel cover screw Starter sprocket check fixing screw S tarter motor fixing screws F lywheel fixing nut F reewheel fixing screws

11 ÷13 5 to 6 11 to 13 100 to 110 10 to 11

FLYWHEEL COVER

CHAR - 12

N am e

To r q u e i n N m

P ick-up screws

3- 4


Characteristics

Nam e

To r q u e i n N m

Stator fixing screws S tator cable plates clamping screws F ixing clamps of head pump cover by-pass pipe Coil fixing screw

5 to 6 (Loctite 242) 3- 4 1.3 to 1.7 11 to 13

CRANKCASE Nam e

To r q u e i n N m

Calibrated fixing dowel Oil filter cover Engine oil level shaft Engine-crankcase coupling screws Rear brake screw Oil sensor Oil filter Oil drain screw Oil pump bulkhead screw F reewheel fixing screws Oil pump fixing screw Oil pump command crown screw Rotor cover Rotor clamp

5- 7 24 to 30 1.3 to 1.7 11 ÷13 15 to 17 12 to 14 5 to 6 14.7 to 16.7 4 to 6 10 to 11 5 to 6 10 to 14 1 to 1.50 3 to 4

HEAD AND CYLINDER Nam e

To r q u e i n N m

Head cover screws Cylinder head nut (P RE -TIGHTENING) Cyli Cylin nder head ead nu nut (TIG (TIGHT HTENIN ENING) G)

10.8 to 12.7 6- 8 9 to 11 11 (Tig (Tigh hten to the pre presc scrribed ibed torqu rque an and then procee oceed d with ith 270.0°± 270.0°±5.0° rotation) rotation) See section E NGINE/LUBRICATION/STUD BOLT 1.3 1.3 to 1.7 1.7 5 to 6 11 to 13 3- 4 7 to 8.5 11 to 13 6 to 9 10 to 12 4 to 6 10.8 to 12.7 3 to 4

Cylinder stud bolt fitting Thro Throtttle body body clam clamp scre screw ws Tens Tensio ion ner spri sprin ng ret retain aining ing screw screw F astener chain tensioner Ther Therm most ostat cove coverr screw screws s P ressure reducer counterweight retainer screw Injection manifold fixing screws Valve clearance adjustment screw Spark plug tightening Timing ing syst system em spro sprock cket et fixi fixing ng screw screw Screws fixing cylinder to crankcase Head blow by

TRANSMISSION AND FINAL REDUCTION Nam e

To r q u e i n N m

Tran Transm smis issio sion n cove coverr screw screws s F inal reduction cover screws Driven pulley fixing nut Oil drain screw F reewheel fixing screws Driving pulley retainer nut

11 to 13 24 to 27 53 to 59 14.7 to 16.7 10 to 11 75 to 83

LUBRICATION Nam e

To r q u e i n N m

Crankcase timing cover screws S crews fixing oil pump to the crankcase P ump rod screw Min Minimum oil oil pr pressu essure re sen senso sorr lock lockin ing g

11 to 13 4 to 6 13 - 15 12 to to 14 14 (LOCTI (LOCTITE TE 50 5091 Edg Edge clo closu surre be between een metal body ody an and plastic block)

Overhaul data

CHAR - 13


Characteristics

As s emb l y cl earan ces

Cylinder - pist on assy.

CYLINDER - PISTON (125) Sp ec i f i c at i o n


P iston diameter Cylinder diameter

51.961 (±0.014) mm 52 (+0.008 -0.020) mm

CYLINDER - PISTON (150) Sp ec i f i c at i o n


P iston diameter Cylinder diameter

57.947 (±0.014) mm 58 (+0.008 -0.020) mm

COUPLING CATEGORIES (125) Nam e

In i t i al s

Cy l i n d er

Pi s t o n

Pl ay o n f i t t i n g

cylinder-piston cylinder-piston cylinder-piston cylinder-piston

A B C D

51.980 to 51.987 51.987 to 51.994 51.994 to 52.001 52.001 to 52.008

51.947 to 51.954 51.954 to 51.961 51.961 to 51.968 51.968 ÷51.975

0.026 ÷0.040 0.026 ÷0.040 0.026 ÷0.040 0.026 ÷0.040

COUPLING CATEGORIES (150) Nam e

In i t i al s

Cy l i n d er

Pi s t o n

Pl ay o n f i t t i n g

cylinder-piston cylinder-piston cylinder-piston cylinder-piston

A B C D

57.980 to 57.987 57.987 to 57.994 57.994 to 58.001 58.001 to 58.008

57.933 to 57.940 57.940 to 57.947 57.947 to 57.954 58.954 to 58.961

0.040 to 0.054 0.040 to 0.054 0.040 to 0.054 0.040 to 0.054

N.B.

THE PISTON MUST MUST BE INSTAL LED WITH THE ARROW FACING TOWARDS THE EXHAUST SIDE, THE PISTON RINGS MUST BE INSTALL ED WITH THE WORD «TOP» OR THE THE STAMPED MARK FACING UPWARDS.

CHAR - 14


Characteristics

- Measure the outer diameter of the gudgeon pin.

Characteristic Pin outside diameter

14 (+0 -0.004) mm

- Measure Measure the diameter diameter of the the housings on the piston.

Characteristic Standard di amete ameter r

14 (+0.006 +0.001) mm

- Carefully clean the seal housings. - Measure the coupling clearance between the sealing rings and the the piston grooves using suitable sensors, as shown in the diagram. - If the clearance is greater than that indicated in the table, replace the piston. - Check the clearance upon mounting (A) of the bands: N.B. MEASURE THE CLEARANCE BY INSERTING THE BLADE OF THE FEELER GAUGE FROM THE SECOND SEAL RING SIDE.

A SSEMBLY CLEARANCE OF BANDS - SEAL DESIGNA TION

1° compression ring (mm) 2° compression ring (mm) Oil ring segments (mm)

DESIGNA TION

(125)

SIZES

A SSEMB L Y CL EA RA NCES (A )

52x0.8 52x1.0 52x2.0

0.20 to 0.35 0.20 to 0.45 0.25 to 0.55

A SSEMBLY CLEARANCE OF BANDS - SEAL 1° compression ring (mm) 2° compression ring (mm) Oil ring segments (mm)

RINGS

RINGS

(150)

SIZES

A SSEMB L Y CL EA RA NCES (A )

58x0.8 58x1.0 58x2.0

0.20 to 0.35 0.20 to 0.45 0.25 to 0.55

- Check that the head coupling surface is not worn or misshapen.

CHAR - 15


Characteristics

- Pistons and cylinders are classified according to diameter. The coupling is carried out in pairs (A-A, B-B, C-C, C-C , D-D). D-D).

Crankcase Crankcase - crankshaft crankshaft - con necting ro d CRANKSHAFT Ti t o l o

Du r at a/Val o r e

Crankshaft

Tes t o B r ev e (< 4000 c ar .)

I n d i r i z z o I m m ag i n e

Axial clearance between crankshaft and connecting rod

Axial clearance between crankshaft and connecting rod

AXIA L CL EARANCE EARA NCE BETWEEN CRANKSHAFT CRANK SHAFT AND A ND CONNECTING CONNECTING ROD Nam e

Half-shaft, transmission side F lywheel-side half shaft Connecting rod Spacer tool

Diamete Diameterr of crankshaft bea bearings. rings.

Measure the bearings on both axes x-y.

CHAR - 16

Co d e

Si zes

A s s em b l y c l ear an c e

A B C E

18.1 (+0; -0.05) mm 18.1 (+0; -0.05) mm 15 (-0.10; -0.15) mm 51.4 (+0; +0.05) mm

D =0.20 - 0.50 D =0.20 - 0.50 D =0.20 - 0.50 D =0.20 - 0.50


Characteristics

CRANKSHAFT Sp ec i f i c at i o n


Crankshaft bearings: Standard diameter: Cat. 1 Crankshaft bearings: Standard diameter: Cat. 2

26.998 to 27.004 mm 27.004 to 27.010 mm

- To obtain a good bushing lubrication it is necessary to have both an optimal lubricating pressure and a good oil flow rate; the bushings must be correctly positioned so as not to obstruct the oil supply channels.

Characteristic «A»

AXIS CYLIND CY LINDER ER

CHAR - 17

Characteristics


- The main bushings have 2 half-bearings, 1 with and 1 without the lubrication channel. - The solid half-bearing is intended to stand the thrusts thrusts caused caused by combustion, combustion, and for this reason it is arranged opposite the cylinder. - To prevent shutters in the oil feeding channels, the matching matching surface surface of the two half-bearings half-bearings must be perfectly orthogonal to the cylinder axis, as shown in the photo.


AXIS CYLIND CY LINDER ER

BUSHINGS TYPE

B C E

CHAR - 18

IDENTIFICA TION

CRA NK SHA FT HA L F-B EA RING

BLUE Y ELLOW GREE N

1.971 to 1.976 1.974 to 1.979 1.977 to 1.982


Characteristics

- The section of the oil feeding channels is also influenced by the driving depth of the bushings. - Visually check the wear of the bushings: in the coupling ends shown s hown in the photo photo the bushing usually keeps the original look, look, check in in the rest of the bushing if there is evident removal of material. If this occurs as stated, proceed to replace the crankcase halves. N.B. SMALL MARKS AND SCRATCHES OF THE SHAFT ROTATION ARE NORMAL SIGNS OF ENGINE USAGE, AND DO NOT AFFECT THE CORRECT FUNCTIONING.

Measurement of crankcase halves - crankshaft coupling clearance.

- The nominal diameters of the bushings, even if of the same coupling category, may differ by hundredths due to the plastic slackening of the material of the crankcase due to the driving load. - Measure along the axis of the « A » cylinder, using a bore meter at two depths indicated in the figure, the diameter of the bushings. - After measuring the two diameters, take the average.


AXIS CYLIND CY LINDER ER - The The bushings housing housing hole in the crankcase half is divided into into two categories categories depending on the size, Category 1 and Category 2.

DIAMETER

OF CRANKCASE WITHOUT BUSHING



CAT 1 CAT 2

30.959 to 30.965 mm 30.953 to 30.959 mm

- Combine the shaft with two category 1 crankwebs with the category 1 crankcase (or cat. 2 with cat. 2). Furthermore a spare crankcase cannot be matched with a crankshaft with mixed categories. The spare crankshaft has half-shafts of the same category. - According to the classification of the shaft CAT.1 - CAT.2 combine a complete crankcase pre-fitted with suitable bushings according to the starting shaft.

CATEGORIES CRA NK CA SE HA L VES

Cat. 1 Cat. 2 Cat. 1 Cat. 2

ENGINE HA L F-SHA FT

B USHING

Cat. 1 Cat. 2 Cat. 2 Cat. 1

E B C C

CHAR - 19

Characteristics


in two two CATEGOTHE CRANKSHAFT is available in RIES:

Characteristic Crankshaft Crankshaft cate category: gory: CAT. 1 - CAT. 2

CRANKSHAFT CATEGORY IDENTIFICATION:

The The iden identtific ificat atio ion n is ind indicat icated ed on the cou counterw erweigh eightt shou should lder er «*1 - *2», if carried out with with micropinholing. Otherwise, «1 - 2» if done manually with an electric pen. The spare part identification is located on the package with a drawing number plus FC1/FC2 or (001/002 ). If a crankshaft comprising comprising two half-shafts of different categories categories needs to be replaced, also replace both crankcase halves, halves, combining the tw two o components components (Shaft (Shaft and Crankcase) Crankcase) featuring the the sam same e category.

Cylin der Head Head Before performing head service operations, thoroughly thoroughly clean all coupling surfaces. Note the position of the springs and the valves so as not to change the original position during refitting - Using a trued bar and a feeler gauge check that the cylinder head surface is not worn or distorted.

Characteristic Maximum Ma ximum allowable run-out:

0.03 mm - In case of faults, replace the head. - Check the sealing surfaces for the exhaust manifold. - Check that the camshaft and the rocking lever pin capacities exhibit no wear. - Check that the head cover show no signs of wear. - Check that there is no cooling liquid leakage from the seals. - Insert the valves into the cylinder head. - Alternatively check the intake and exhaust valves. - The test is carried out by filling the manifold with petrol and checking that the head does not ooze through the valves when these are just pressed with the fingers.

CHAR - 20


Characteristics

HEAD BEARINGS



bearing «A» bearing «B» bearing «C»

Ø 10.000 (+0.015) mm Ø 28.000 (+0.007 +0.028) mm Ø 42.000 (+0.009 +0.034) mm

Measure the unloaded spring length

Characteristic Standard length

35.8 mm

- Remove any carbon deposits from the valve seats. - Check the width of the mark on the valve seat «V» with Prussian blue.

Characteristic Standard value:

1 - 1.3 mm

- If the width of the mark on the valve seat is larger than the prescribed limits, true the seats with a 45° milling cutter and then grind. - In case of excessive wear or damage, replace the head.

CHAR - 21


Characteristics

- Measure the diameter of the valve stems in the three positions indicated in the diagram.

STANDARD DIAMETER Sp ec i f i c at i o n


Intake: Exhaust:

4.030 to 4.015 mm 4.975 to 4.960 mm

- Calculate the clearance between valve and valve guide. - Check the deviation of the valve stem by resting it on a «V» shaped support and measuring the extent of the deformation using a dial gauge.

Characteristic Limit values admitted: admitted:

0.02 mm

- Check the oscillation of the valve head by arranging a dial gauge at right angle relative to the valve head and rotate rotate it on a "V" shaped shaped abutment.

Characteristic Admi Ad miss ss ible ib le lim l im it :

0.3 mm

Measure the valve guide.

Characteristic Valve guide:

4.3 ±0.1 mm

CHAR - 22


Characteristics

- After After meas measuring uring the valve guide diamet diameter er and the valve stem diameter, check clearance between guide and stem.

INTAKE Sp ec i f i c at i o n


S tandard clearance: Admissible limit:

0.10 mm 0.08 mm

EXHAUST Sp ec i f i c at i o n


S tandard clearance: Admissible limit:

0.15 mm 0.1 mm

- Check that there are no signs of wear on the mating surface with the set screw articulated terminal.

- If no faults are found during the above checks, you can use the same valves. To obtain better sealing performance, grind the valve seats. Grind the valves gently with a fine-grained lapping compound. During the grinding grinding,, keep the cylinder head with the the valve axes in a horizontal position. This T his will prevent the lapping compound residues from penetrating between the valve stem and the guide (see figure). CAUTION

TO AVOID SCORING THE FAYING SURFACE, DO NOT KEEP ROTA TING THE VALVE WHEN NO LAPPING COMPOUND IS LEFT. CAREFULLY WASH THE CYLINDER HEAD AND THE VALVES WITH A SUITABLE PRODUCT FOR THE TYPE OF LAPPING COMPOUND BEING USED. CAUTION

DO NOT REVERSE THE FITTING POSITIONS OF THE VALVES (RIGHT - LEFT).

- Check that the camshaft bearings exhibit no scores or abnormal wear. - Using a micrometer, measure the camshaft bearings. CHAR - 23

Vespa LX - S 125 - 150 i.e. 3V MY 2012 (EN)

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