Piaggio Vespa WORKSHOP NRG Power Purejet Workshop Manual

WORKSHOP MANUAL

633265

NRG Power Purejet

WORKSHOP

MANUAL

NRG Power Purejet

The descriptions and illustrations given in this publication are not binding. While the basic specifications
as described and illustrated in this manual remain unchanged, PIAGGIO-GILERA reserves the right, at

any time and without being required to update this publication beforehand, to make any changes to

components, parts or accessories, which it considers necessary to improve the product or which are

required for manufacturing or construction reasons.

Not all versions shown in this publication are available in all Countries. The availability of single versions

should be checked at the official Piaggio sales network.

"© Copyright 2007 - PIAGGIO & C. S.p.A. Pontedera. All rights reserved. Reproduction of this publication

in whole or in part is prohibited."

PIAGGIO & C. S.p.A. - After-Sales

V.le Rinaldo Piaggio, 23 - 56025 PONTEDERA (Pi)

WORKSHOP MANUAL

NRG Power Purejet

This workshop manual has been drawn up by Piaggio & C. Spa to be used by the workshops of Piaggio­Gilera dealers. This manual is addressed to Piaggio service mechanics who are supposed to have a
basic knowledge of mechanics principles and of vehicle fixing techniques and procedures. Any important
changes made to the vehicles or to specific fixing operations will be promptly reported by updates to this
manual. Nevertheless, no fixing work can be satisfactory if the necessary equipment and tools are
unavailable. It is therefore advisable to read the sections of this manual relating to specific tools, along
with the specific tool catalogue.

N.B. Provides key information to make the procedure 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.

Safeguarding the environment Sections marked with this symbol 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

MAINTENANCE MAIN

TROUBLESHOOTING TROUBL

ELECTRICAL SYSTEM ELE SYS

ENGINE FROM VEHICLE ENG VE

ENGINE ENG

SUSPENSIONS SUSP

PURE JET INJECTION INJ PJ

BRAKING SYSTEM BRAK SYS

COOLING SYSTEM COOL SYS

CHASSIS CHAS

PRE-DELIVERY PRE DE

TIME TIME

INDEX OF TOPICS

CHARACTERISTICS CHAR

Characteristics NRG Power Purejet

Rules

This section describes general safety rules for any maintenance operations performed on the vehicle.

Safety rules

- If work can only be done on the vehicle with the engine running, make sure that the premises are well­ventilated, 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 open 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.

Maintenance 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 solvent. Lubricate all the
work surfaces except the tapered couplings before refitting.

- After refitting, make sure that all the components have been installed correctly and work properly.

- For removal, overhaul and refit operations use only tools with metric measures. Metric bolts, nuts and
screws are not interchangeable with coupling members with English measurement. Using unsuitable
coupling members and tools may damage the scooter.

- When carrying out maintenance operations on the vehicle that involve the electrical system, make
sure the electric connections have been made properly, particularly the ground and battery connections.

CHAR - 2

NRG Power Purejet Characteristics

Vehicle identification

Frame prefix: ZAPC45200 ÷ 1001
Engine prefix: C452M

Dimensions and mass

Specification Desc./Quantity

Max length 1790 mm.

Max width 850 mm.
Seat height 795 mm.
Wheelbase 1280 mm

Dry weight 99 kg.

DIMENSIONS AND MASS

CHAR - 3

Characteristics NRG Power Purejet

Engine

ENGINE

Specification Desc./Quantity

Engine type 2 stroke single cylinder Piaggio HI-PER2 PRO

PUREJET

Bore x stroke 40 X 39.3 mm

Cubic capacity 49.40 cc

Compression ratio 9.4 to 10.4 :1

Throttle body BING Ø18mm

Engine idle speed 1800 to 2000 r.p.m.

Air filter Sponge impregnated with fuel mixture (50% SE-

LENIA air filter oil and 50% unleaded petrol).
Starting system electric starter/kickstarter
Cooling system forced coolant circulation system

Lubrication Engine lubrication (piston, cylinder, crankshaft,

main bearings) with mixer oil.

Fuel supply With electric fuel pump, controlled by the ECU and

unleaded petrol (with 95 octane minimum) via

throttle body

Cooling system Through circulation of cooling liquid

CHAR - 4

NRG Power Purejet Characteristics

Transmission

TRANSMISSION

Specification Desc./Quantity

Transmission With automatic expandable pulley variator, torque

server, V belt, automatic clutch, gear reduction

unit.

Capacities

CAPACITIES

Specification Desc./Quantity

Rear hub oil Quantity: approx. 75 cm³

Mixer oil 1.2 litres

Fuel tank capacity 6.5 litres (1.5 litres of reserve)

Electrical system

Specification Desc./Quantity

Ignition type Electronic ignition system with integrated H.T. coil

Ignition advance (before TDC) variable (integrated into the ignition system)

Recommended spark plug type CHAMPION RG6YCA

Battery 12V-9Ah

Main fuse 20A

Generator Three-phase alternating current

Frame and suspensions

Specification Desc./Quantity

Chassis type Welded tubular steel chassis with stamped sheet

Front suspension upside-down hydraulic telescopic fork.

Front suspension travel 75 mm

Rear suspension With coaxial spring and hydraulic shock absorber.

Brakes

ELECTRICAL SYSTEM

managed by ECU

FRAME AND SUSPENSIONS

reinforcements

Chassis to engine support with swinging arm.

BRAKES

Specification Desc./Quantity

Front brake Ø 220 mm disc brake with hydraulic linkage (r.h.

brake lever).

Rear brake Ø 175 mm disc (hydraulically controlled via lever

on left hand-side of handlebar)

CHAR - 5

Characteristics NRG Power Purejet

Wheels and tyres

WHEELS AND TYRES

Specification Desc./Quantity

Front tyre Tubeless 120/70-13"

Rear tyre Tubeless 140/60 x 13''

Wheels With circles of 3.50 x 13" in light alloy.

Tightening Torques

STEERING ASSEMBLY

Name Torque in Nm

Upper steering ring nut (safety locks) 35 to 40 Nm
Lower steering ring nut (safety locks) 8 to 10 Nm

Handlebar fixing pin (safety locks) 45 to 50 Nm

FRAME ASSEMBLY

Name Torque in Nm

Swinging arm-engine pin (safety locks) 33 to 41 Nm

Swinging arm-frame pin (safety locks) 64 to 72 Nm

Shock absorber - frame nut (safety locks) 20 to 25 Nm

Shock absorber-engine pin (safety locks) 33 to 41 Nm

Rear wheel axis (safety locks) 104 to 126 Nm

Bolt holding stand to the engine 18 to 19 Nm

Side stand fixing screw 12 ÷ 20

Side stand bracket fixing screw 15 ÷ 20

Rear rim fixing screw 20÷25

FRONT SUSPENSION

Name Torque in Nm

Front wheel axle nut (safety locks) 45 to 50 Nm

Wheel axle clamp screw 6 ÷ 7 Nm

Lower leg screw 15 to 20 Nm

Hydraulic cartridge stem nut 15 to 18 Nm

FRONT BRAKE

Name Torque in Nm

Viti fissaggio coperchio pompa freno 1,5 ÷ 2 Nm

Brake pump support fixing screw 7 to 10 Nm

Brake fluid pump - hose fitting 13 to 18 Nm

Brake fluid tube - calliper fitting 20 to 25 Nm

Calliper tightening screw 20 to 25 Nm

Disc tightening screw (safety locks - lock with

LOCTITE THREADLOCK MEDIUM TYPE 243)

Oil bleed screw 7 to 10 Nm

Calliper coupling screw 20 to 25 Nm

6 ÷ 7 Nm

REAR BRAKE

Name Torque in Nm

Fastening screws calliper to the crankcase 20 - 25

CHAR - 6

NRG Power Purejet Characteristics

Name Torque in Nm

Brake reservoir cover fixing screw 2÷4 N·m (Grimeca) - 0,8÷1,5 N·m (Brembo) -

1,5÷2 N·m (Hengtong)

Brake pump support fixing screw 7 to 10 Nm

Brake fluid pump - hose fitting 13 to 18 Nm

Brake fluid tube - calliper fitting 20 to 25 Nm

Oil bleed screw 7 to 10 Nm

ENGINE UNIT

Name Torque in Nm

Clutch bell nut 40 to 44 Nm

Clutch lock ring nut 55 ÷ 60

nut locking driving pulley on the crankshaft 40 to 44 Nm

Start-up lever screw 12 ÷ 13

Flywheel nut 40 to 44 Nm

Flywheel fan screws 3 ÷ 4

Half-crank case joint bolts 12 ÷ 13

Bolts holding exhaust pipe to the crankcase 22 ÷ 24

Screws holding the filter box to the crank case 4 ÷ 5

Head nuts 10 ÷ 11

Temperature ECU sensor 18÷22 N·m

Termistore 6÷8 N·m

Starter screws 12 ÷ 13

Ignition spark plug 25 ÷ 30
Hub oil drainage cap 3 ÷ 5
Oil hub level dipstick Manual

Rear hub cap screws 12 ÷ 13

Transmission cover screws 12 ÷ 13

Inlet manifold screws 8 ÷ 9

Flywheel hood fixing screws 1 ÷ 2

Cylinder hood fixing screws 3.5 ÷ 5

Stator clamping screws 3 ÷ 4

Pick-Up clamping screw 4 ÷ 5

Mixer clamping screws 3 ÷ 4

Screw fixing brake lever to the journal on the en-

gine

12 ÷ 13

Overhaul data

Assembly clearances

Cylinder - piston assy.

CYLINDER-PISTON FITTING

Name Initials Cylinder Piston Play on fitting

Standard fitting M 39.997-40.004 39.943-39.95 0.047-0.061
Standard fitting N 40.004-40.011 39.95-39.957 0.047-0.061
Standard fitting O 40.011-40.018 39.957-39.964 0.047-0.061

Standard fitting P 40.018-40.025 39.964-39.971 0.047-0.061
1st oversize fitting M1 40.197-40.204 40.143-40.15 0.047-0.061
1st oversize fitting N1 40.204-40.211 40.15-40.157 0.047-0.061

CHAR - 7

Characteristics NRG Power Purejet

Name Initials Cylinder Piston Play on fitting

1st oversize fitting O1 40.211-40.218 40.157-40.164 0.047-0.061

1st oversize fitting P1 40.218-40.225 40.164-40.171 0.047-0.061
2nd oversize fitting M2 40.397-40.404 40.343-40.35 0.047-0.061
2nd oversize fitting N2 40.404-40.411 40.35-40.357 0.047-0.061
2nd oversize fitting O2 40.411-40.418 40.357-40.364 0.047-0.061
2nd oversize fitting P2 40.418-40.425 40.364-40.371 0.047-0.061

Piston rings

SEALING RINGS

Name Description Dimensions Initials Quantity

Compression ring 40 A 0.10 to 0.25
Compression ring

1st oversize

Compression ring

2nd Oversize

40.2 A 0.10 to 0.25

40.4 A 0.10 to 0.25

Crankcase - crankshaft - connecting rod

AXIAL CLEARANCE BETWEEN CRANKCASE, CRANKSHAFT AND CONNECTING ROD

Name Description Dimensions Initials Quantity

Connecting rod 11.750-0.05 A clearance E = 0.25

to 0.50

shoulder washer 0.5 ± 0.03 G clearance E = 0.25

to 0.50 - clearance

F = 0.20 to 0.75

CHAR - 8

NRG Power Purejet Characteristics

Name Description Dimensions Initials Quantity

Half-shaft, trans-

mission side

Flywheel-side half-

shaft

Lining between the

shoulders

Cage 11.800-0.35 B clearance F = 0.20

13.75+0.040 C clearance E = 0.25
to 0.50 - clearance

F = 0.20 to 0.75

13.75+0.040 D clearance E = 0.25
to 0.50 - clearance

F = 0.20 to 0.75

40.64 H clearance E = 0.25
to 0.50 - clearance

F = 0.20 to 0.75

to 0.75

Slot packing system

- Fit the cylinder without installing the basic gasket.

- Apply a centimetre dial gauge on the special tool
and zero it on the ground plane

- Fit the tool to the top of the cylinder fixing it with
two nuts to the studbolts and take the piston to the
T.D.C.

- The thickness of the gasket to fit will change de­pending on the value detected. For this purpose,
there are three with different thicknesses

Specific tooling

020272Y Piston position check tool

SHIMMING SYSTEM

Name Measure A Thickness

Shimming 2.80 ÷ 3.04 0,4
Shimming 3.04 ÷ 3.24 0,6
Shimming 3.25 ÷ 3.48 0,8

CHAR - 9

Characteristics NRG Power Purejet

Products

TABLE OF RECOMMENDED PRODUCTS

Product Description Specifications

AGIP ROTRA 80W-90 Rear hub oil SAE 80W/90 Oil that exceeds the

requirements of API GL3 specifi-

cations

AGIP CITY HI TEC 4T Oil for flexible transmission lubri-

cation (brake, throttle control and

mixer, odometer

AGIP FILTER OIL Oil for air filter sponge Mineral oil with specific additives

AGIP CITY TEC 2T Mixer oil synthetic oil for 2-stroke engines:

AGIP GP 330 Grease for brake levers, throttle White calcium complex soap-

AGIP GREASE SM 2 Grease for the tone wheel revolv-

ing ring

AGIP BRAKE 4 Brake fluid FMVSS DOT4 Synthetic fluid

MONTBLANC MOLYBDENUM

GREASE

AGIP GREASE PV2 Grease for the steering bearings,

Grease for driven pulley shaft ad-

justing ring and movable driven

pulley housing

pin seats and swinging arm

Oil for 2-stroke engines: SAE

5W-40, API SL, ACEA A3, JASO

MA

for increased adhesiveness

JASO FC, ISO-L-EGD

based spray grease with NLGI 2;

ISO-L-XBCIB2

Soap-based lithium grease con-

taining NLGI 2 Molybdenum di-

sulphide; ISO-L-XBCHB2, DIN

KF2K-20

Molybdenum disulphide grease

White anhydrous-calcium based

protective grease for roller bear-

ings; temperature range be-

tween -20 C and +120 C; NLGI 2;

ISO-L-XBCIB2.

CHAR - 10

INDEX OF TOPICS

TOOLING TOOL

Tooling NRG Power Purejet

TOOLING

Stores code Description

001330Y Tool for fitting steering seats

001467Y006 Pliers to extract 20 mm bearings

001467Y007 Driver for OD 54 mm bearing

001467Y008 Pliers to extract 17 mm ø bear-

ings

001467Y009 Driver for OD 42 mm bearings

001467Y013 Pliers to extract ø 15-mm bear-

ings

TOOL - 2

001467Y014 Pliers to extract ø 15-mm bear-

ings

NRG Power Purejet Tooling

Stores code Description

001467Y017 Bell for bearings, outside Ø 39

mm

001467Y021 Extraction pliers for ø 11 mm

bearings

001467Y029 Bell for bearings, O.D. 38 mm

002465Y Pliers for circlips

004499Y Camshaft bearing extractor

TOOL - 3

Tooling NRG Power Purejet

Stores code Description

004499Y007 Half rings

006029Y Punch for fitting fifth wheel seat

on steering tube

020004Y Punch for removing fifth wheels

from headstock

020055Y Wrench for steering tube ring nut

020074Y Support base for checking crank-

shaft alignment

020080Y Punch for removing 12-mm bear-

ings

TOOL - 4

020150Y Air heater support

NRG Power Purejet Tooling

Stores code Description

020151Y Air heater

020162Y Flywheel extractor

020163Y Crankcase splitting plate

020164Y Driven pulley assembly sheath

020166Y Pin lock fitting tool

020168Y Water seal punch mount on half-

crankcase

TOOL - 5

Tooling NRG Power Purejet

Stores code Description

020169Y Water pump crankshaft fitting

and removal spanner

020170Y Water pump/mixer command

gear extractor

020171Y Punch for driven pulley roller

bearing

020209Y Spring hook

020265Y Bearing fitting base

TOOL - 6

NRG Power Purejet Tooling

Stores code Description

020272Y Piston position check tool

020325Y Brake-shoe spring calliper

020329Y MityVac vacuum-operated pump

020330Y Stroboscopic light for timing con-

trol

020331Y Digital multimeter

TOOL - 7

Tooling NRG Power Purejet

Stores code Description

020332Y Digital rev counter

020334Y Multiple battery charger

020335Y Magnetic support for dial gauge

020340Y Flywheel and transmission oil

seals fitting punch

TOOL - 8

020357Y 32 x 35 mm adaptor
020358Y 37x40-mm adaptor
020359Y 42x47-mm adaptor

020362Y 12-mm guide

NRG Power Purejet Tooling

Stores code Description

020363Y 20 mm guide

020409Y Multimeter adaptor - Peak volt-

age detection

020376Y Adaptor handle

020412Y 15 mm guide

020439Y 17 mm guide

020444Y Test probe removal / fitting tool

TOOL - 9

Tooling NRG Power Purejet

Stores code Description

020456Y Ø 24 mm adaptor

020451Y Start-up crown lock

020452Y Tube for removing and refitting

the driven pulley shaft

020460Y Scooter diagnosis and tester

020481Y Control unit interface wiring

TOOL - 10

NRG Power Purejet Tooling

Stores code Description

020565Y Flywheel lock calliper spanner

020469Y Reprogramming kit for scooter

diagnosis tester

020614Y Diagnostic tester programming

software

020615Y Carbon dam ring fitting kit

020616Y Fuel pressure control kit

020617Y Air pressure check kit

TOOL - 11

Tooling NRG Power Purejet

Stores code Description

020620Y Water pump impeller stop

020621Y HV cable extraction adaptor

TOOL - 12

INDEX OF TOPICS

MAINTENANCE MAIN

Maintenance NRG Power Purejet

Maintenance chart

EVERY 2 YEARS

Action

Brake fluid - change
Coolant - change

AFTER 1000 KM

50'

Action

Hub oil - change
Oil mixer/throttle linkage - adjustment
Odometer cable - greasing
Steering - adjustment
Brake control levers - greasing
Brake fluid level - check
Safety locks - check
Electrical system and battery - check
Tyre pressure and wear - check
Vehicle and brake test - road test

AT 5000 KM OR 12 MONTHS, 25000 KM, 35000 KM AND 55000 KM

40'

Hub oil level - check
Spark plug/electrode gap - replacement
Air filter - clean
Oil mixer/throttle linkage - adjustment
Coolant level - check
Brake control levers - greasing
Brake pads - check condition and wear
Brake fluid level - check
Electrical system and battery - check
Tyre pressure and wear - check
Vehicle and brake test - road test

AT 10000 KM OR 24 MONTHS AND 50000 KM

95'

Hub oil - change
Spark plug/electrode gap - replacement
Air filter - clean
Idling speed (*) - adjustment
Oil mixer/throttle linkage - adjustment
Variable speed rollers - replacement
Odometer cable - greasing
Driving belt - check
Coolant level - check
Steering - adjustment
Brake control levers - greasing
Brake pads - check condition and wear

Action

Action

MAIN - 2

NRG Power Purejet Maintenance

Action

Brake fluid level - check
Transmission elements - lubrication
Safety locks - check
Suspensions - check
Electrical system and battery - check
Headlight - adjustment
Tyre pressure and wear - check
Vehicle and brake test - road test

(*) See CO regulation in the «Adjusting the engine idle» section

AT 15000 KM AND 45000 KM

65'

Action

Hub oil level - check
Spark plug/electrode gap - replacement
Air filter - clean
Oil mixer/throttle linkage - adjustment
Driving belt - replacement
Coolant level - check
Brake control levers - greasing
Brake pads - check condition and wear
Brake fluid level - check
Electrical system and battery - check
Tyre pressure and wear - check
SAS box (sponge) (**) - cleaning
Vehicle and brake test - road test

(**) See the regulations of the "Secondary air system" section

AT 20000 KMS AND 40000 KMS

120'

Hub oil - change
Spark plug/electrode gap - replacement
Air filter - clean
Idling speed (*) - adjustment
Cylinder cooling system - check/cleaning
Oil mixer/throttle linkage - adjustment
Driving belt - check
Variable speed rollers - replacement
Mixer belt - replacement
Coolant level - check
Radiator - external cleaning/ check
Odometer cable - greasing
Steering - adjustment
Brake control levers - greasing
Brake pads - check condition and wear
Brake fluid level - check
Transmission elements - lubrication
Safety locks - check
Suspensions - check
Electrical system and battery - check
Headlight - adjustment
Tyre pressure and wear - check

Action

MAIN - 3

Maintenance NRG Power Purejet

Action

Vehicle and brake test - road test

(*) See CO regulation in the «Adjusting the engine idle» section

AT 30000 KM

130'

Action

Hub oil - change
Spark plug/electrode gap - replacement
Air filter - clean
Idling speed (*) - adjustment
Oil mixer/throttle linkage - adjustment
Driving belt - replacement
Variable speed rollers - replacement
Coolant level - check
Odometer cable - greasing
Steering - adjustment
Brake control levers - greasing
Brake pads - check condition and wear
Flexible brake tubes - replacement
Brake fluid level - check
Transmission elements - lubrication
Safety locks - check
Suspensions - check
Electrical system and battery - check
Headlight - adjustment
Tyre pressure and wear - check
SAS box (sponge) (**) - cleaning
Vehicle and brake test - road test

(*) See CO regulation in the «Adjusting the engine idle» section
(**)See rules in the «Secondary Air System» section

160'

Hub oil - change
Spark plug/electrode gap - replacement
Air filter - clean
Idling speed (*) - adjustment
Oil mixer/throttle linkage - adjustment
Driving belt - replacement
Variable speed rollers - replacement
Mixer belt - replacement
Coolant level - check
Radiator - external cleaning/ check
Odometer cable - greasing
Steering - adjustment
Brake control levers - greasing
Brake pads - check condition and wear
Flexible brake tubes - replacement
Brake fluid level - check
Transmission elements - lubrication
Safety locks - check
Suspensions - check

AT 60000 KM

Action

MAIN - 4

NRG Power Purejet Maintenance

Action

Electrical system and battery - check
Headlight - adjustment
Tyre pressure and wear - check
SAS box (sponge) (**) - cleaning
Vehicle and brake test - road test

(*) See CO regulation in the «Adjusting the engine idle» sectionp>
(**) Vedere norme della sezione «Sistema aria secondaria»

Spark plug

- Position the vehicle on its centre stand;

- Remove the centre cover by unscrewing the 2 set
screws;

- Disconnect the cover from the plug lead;

- Unscrew the spark plug using a spark plug span­ner;

- Check the conditions of the spark plug, make
sure the insulation is intact and measure the gap
between the electrodes with a feeler.

- Adjust the gap if necessary, carefully bending the
side electrode.
In the event of defects replace the spark plug with
the prescribed type;

- Position the spark plug at the correct angle and
manually tighten it all the way down, then use the
specific spanner to tighten it to the prescribed tor­que;

- Put the cover back over the spark plug;

- Reassemble the central cover.

CAUTION

THE SPARK PLUG MUST BE REMOVED WHEN
THE MOTOR IS COLD. THE SPARK PLUG
MUST BE REPLACED EVERY 5000 KM. USE
OF STARTERS NOT CONFORMING OR SPARK
PLUGS NOT THOSE DESCRIBED CAN SERI­OUSLY DAMAGE THE ENGINE.

Characteristic

Recommended spark plug type

CHAMPION RG6YCA

Electric characteristic

Electrode gap

MAIN - 5

Maintenance NRG Power Purejet

0,55÷0,65 mm

Locking torques (N*m)

Spark plug 25 - 30 Nm

Hub oil

Check

Do the following to check the correct level:

1) Stand the vehicle on the centre-stand on flat
ground;

2) Remove the dipstick «A», and dry it with a clean
cloth. Reinsert it, screwing it in all the way;

3) Remove the stick and check that the oil level is
slightly over the second notch starting from the
lower end;

4) Screw the dipstick back in, checking that it is
locked in place.

Recommended products

AGIP ROTRA 80W-90 Rear hub oil

SAE 80W/90 Oil that exceeds the requirements of
API GL3 specifications

Replacement

- Remove oil filler cap «A».

- Loosen oil draining cap «B» and allow for the
system to drain completely.

- Refit the draining cap and refill the hub with the
prescribed oil.

Characteristic

Rear hub oil

~ 85 cc

MAIN - 6

NRG Power Purejet Maintenance

Air filter

-Remove the cap of the purifier, unscrewing the six
clamping screws and removing the filter.
Cleaning:

-Wash with water and neutral soap.

- Dry with a clean cloth and short blasts of com­pressed air.

-Saturate with a 50% mixture of gasoline and oil.

-Drip dry the filter and then squeeze it between the
hands without wringing.

-Let it dry and refit it again.

CAUTION

NEVER RUN THE ENGINE WITHOUT THE AIR
FILTER, THIS WOULD RESULT IN AN EXCES­SIVE WEAR OF THE PISTON AND CYLINDER.

Recommended products

AGIP FILTER OIL Oil for air filter sponge

Mineral oil with specific additives for increased ad­hesiveness

Checking the ignition timing

- Adjust the control cables:
Mix cable: see procedure indicated in "Mixer tim­ing".
Throttle cable: adjust the set screw on the carbu­rettor in such a way that the sheath has no back­lash.
Splitter control cable: adjust set screw on the throt­tle control to the handlebar in such a way that there
is no backlash on the throttle control.
Adjust all transmissions in such a way that their
sheathings show no sign of backlash.

Mixer Timing

- Using the transmission set screw on the crank­case, with throttle control untwisted, adjust the
reference mark on the rotating plate so that it is

MAIN - 7

Maintenance NRG Power Purejet

lined up with the reference mark on the mixer
body, as shown in the figure.
While doing this, the engine must be fuelled with a
2 % oil mixture (0.5 litre minimum if the reservoir
is empty).

CAUTION

IN CASE OF DISMANTLING OR RUNNING OUT
OF OIL IN THE RESERVOIR BLEED THE MIXER
AS FOLLOWS: REFILL THE OIL RESERVOIR
WHEN THE MIXER IS FITTED TO THE VEHICLE
AND THE ENGINE IS OFF, UNDO THE MIXER
PIPE FROM THE CARBURETTOR AND LOOS­EN THE BLEED SCREWS (SEE THE ARROW IN
THE FIGURE) UNTIL THE OIL BEGINS TO
FLOW OUT. TIGHTEN THE SCREWS, START
UP THE ENGINE AND WAIT FOR OIL TO FLOW
OUT OF THE TUBE. RECONNECT THE DELIV­ERY PIPE TO THE CARBURETTOR AND FIX IT
IN PLACE WITH THE RELEVANT METAL CLIP.

Recommended products

AGIP CITY TEC 2T Mixer oil

synthetic oil for 2-stroke engines: JASO FC, ISO­L-EGD

Braking system

Level check

Proceed as follows:

- Rest the vehicle on its centre stand with the han­dlebars perfectly horizontal;

- Check the level of liquid with the related warning
light «A».
A certain lowering of the level is caused by wear
on the pads.

MAIN - 8

NRG Power Purejet Maintenance

Top-up

Proceed as follows:

- Remove the tank cap by loosening the two
screws, remove the gasket and top up using only
the liquid specified without exceeding the maxi­mum level.

CAUTION

ONLY USE DOT 4-CLASSIFIED BRAKE FLUID.

CAUTION

MAKE SURE THE BRAKE FLUID DOES NOT
GET INTO YOUR EYES OR ON YOUR SKIN OR
CLOTHES. IF THIS HAPPENS ACCIDENTALLY,
WASH WITH WATER.

CAUTION

BRAKE CIRCUIT FLUID IS VERY CORROSIVE;
MAKE SURE THAT IT DOES NOT COME INTO
CONTACT WITH THE PAINTWORK.

CAUTION

THE BRAKE FLUID IS HYGROSCOPIC, IN OTH­ER WORDS, IT ABSORBS MOISTURE FROM
THE SURROUNDING AIR. IF THE CONTENT OF
MOISTURE IN THE BRAKING FLUID EXCEEDS
A CERTAIN VALUE, BRAKING WILL BE INEF­FICIENT.
NEVER USE BRAKE LIQUID IN OPEN OR PAR­TIALLY USED CONTAINERS.
UNDER NORMAL CLIMATIC CONDITIONS,
THE FLUID MUST BE CHANGED EVERY 20,000
KM OR ANYWAY EVERY TWO YEARS.

N.B.

SEE THE BRAKING SYSTEM CHAPTER WITH
REGARD TO THE CHANGING OF BRAKE FLU­ID AND THE BLEEDING OF AIR FROM THE
CIRCUITS.

Recommended products

AGIP BRAKE 4 Brake fluid

FMVSS DOT4 Synthetic fluid

Headlight adjustment

Proceed as follows:

1. Place the vehicle in running order and with the
tyres inflated to the prescribed pressure, on a flat
surface 10 m away from a white screen situated in
a shaded area, making sure that the longitudinal
axis of the vehicle is perpendicular to the screen;

MAIN - 9

Maintenance NRG Power Purejet

2. Turn on the headlight and check that the bor­derline of the projected light beam on the screen
is not lower than 9/10 of the distance from the
ground to the centre of vehicle headlamp and high­er than 7/10;

3. Otherwise, regulate the headlight by adjusting
the screw «A», after removing the front grille.

N.B.

THE ABOVE PROCEDURE COMPLIES WITH
THE EUROPEAN STANDARDS REGARDING
MAXIMUM AND MINIMUM HEIGHT OF LIGHT
BEAMS. REFER TO THE STATUTORY REGU­LATIONS IN FORCE IN EVERY COUNTRY
WHERE THE vehicle IS USED.

MAIN - 10

INDEX OF TOPICS

TROUBLESHOOTING TROUBL

Troubleshooting NRG Power Purejet

This section makes it possible to find the solutions to use in troubleshooting.
For each breakdown, a list of the possible causes and respective interventions is given.

Engine

Poor performance

POOR PERFORMANCE

Possible Cause Operation

Defective fuel pump or damaged depression line Replace the pump or control lines

Fuel filter dirty or clogged Clean the coupling filter

Excess of encrustations in the combustion cham-

ber

Lack of compression wear of the piston rings or

cylinder

Exhaust pipe clogged due to excessive encrusta-

tions

Air filter blocked or dirty Clean according to the procedure

Clutch slipping Check the centrifugal brake shoe assembly and /

Defective mobile pulley sliding Check the parts, change the faulty parts and lubri-

Transmission belt worn Replace

Roller wear; Presence of oil; Dirt Clean the speed variator, replace the rollers if worn

Replace the exhaust pipe and check the carbura-

cate the driven pulley using only Montblanc-Mo-

Remove the encrustations

Check the worn parts and replace them

tion and mixer timer

or clutch bell and replace if necessary

libdenum Grease (dis. 498345) grease

out

Rear wheel spins at idle

REAR WHEEL

Possible Cause Operation

Intake manifold cracked or incorrectly tightened Make sure the manifold is not damaged and that it

is correctly tightened on the throttle body and

crankcase

Clutch fault Check the spring/friction mass and the clutch bell

Starting difficulties

DIFFICULTY IN STARTING

Possible Cause Operation

Defective fuel pump or damaged depression line Replace the pump or control lines

Battery flat Check the state of the battery. If it shows signs of

sulphation replace it and bring the new battery into

service charging it for eight hours at a current of

1/10 of the capacity of the battery itself

Altered fuel characteristics Drain off the fuel no longer up to standard; then,

refill

Defective spark plug or with incorrect electrode

gap

Remove the encrustation, restore the plug gap or

replace being sure to use the types of spark plug

TROUBL - 2

NRG Power Purejet Troubleshooting

Possible Cause Operation

recommended at all times. Bear in mind that many
problems engines have, derive from the use of the

wrong spark plug

Intake joint cracked or with a bad seal Replace the intake joint and check its tightness on

the crankcase and on the carburettor

Purifier-carburettor fitting damaged Replace

Excessive oil consumption/Exhaust smoke

EXCESSIVE OIL CONSUMPTION/SMOKEY EXHAUST

Possible Cause Operation

Excess of encrustations in the combustion cham-

ber

Engine tends to cut-off at idle

Remove the encrustations

ENGINE IDLE

Possible Cause Operation

Reed valve does not close Check / replace the reed pack

Spark plug defective or faulty Replace the spark plug with one with the specified

Transmission and brakes

Clutch grabbing or performing inadequately

CLUTCH

Possible Cause Operation

Tear or irregular functioning Check that the masses open and return normally

Check that there is no grease on the masses
Check that the clutch masses' contact surface with
the clutch bell is mainly in the middle with charac-

teristics equivalent on the three masses

Check that the clutch bell is not scored or worn

Never operate the engine without the clutch bell

degree and check the plug gap

abnormally

Insufficient braking

Possible Cause Operation

Poor braking The rear (drum type) brake is adjusted by regulat-

BRAKE SYSTEM FAULT

ing the special adjustment (on the wheel) bearing
in mind that, with the control levers in the rest po-

sition, the wheels must turn freely.

The braking action should begin when the brake

levers are pressed by about a third.

Check the brake pad wear.

TROUBL - 3

Troubleshooting NRG Power Purejet

Possible Cause Operation

If it is not possible to remove any problems by sim-

ply adjusting the transmissions, check the brake

pads and front brake disc, the brake shoes and the

rear drum. If you encounter excessive wear or

scoring, make the necessary replacements.

Air bubbles inside the hydraulic braking system Carefully bleed the hydraulic braking system,

(there must be no flexible movement of the brake

lever).

Fluid leakage in hydraulic braking system Elastic fittings, piston seals or brake pump break-

down, replace

The brake fluid has lost its properties Replace the front brake fluid and top up to the cor-

rect level in the pump

Brake noise Check the wear of the brake pads and/or shoes

Brakes overheating

BRAKE OVERHEATING

Possible Cause Operation

Defective piston sliding Check calliper and replace any damaged part.

Deformed brake disc Use a comparator to check the disc planarity with

the wheel correctly mounted

Electrical system

Battery

Possible Cause Operation

Battery The battery is the electrical device in the system

Steering and suspensions

BATTERY

that requires the most frequent inspections and

thorough maintenance. If the vehicle is not used

for some time (1 month or more) the battery needs

to be recharged periodically. The battery runs
down completely in the course of 5 ÷ 6 months. If
the battery is fitted on a motorcycle, be careful not
to invert the connections, keeping in mind that the
black ground wire is connected to the negative ter­minal while the red wire is connected to the termi­nal marked+. Follow the instructions in the ELEC­TRICAL SYSTEM chapter for the recharging of the

batteries.

TROUBL - 4

NRG Power Purejet Troubleshooting

Rear wheel

POOR ROAD HOLDING

Possible Cause Operation

Faulty suspension Check that the rear shock absorber and/or the

front fork is/are in good working order. Replace or

overhaul the front fork and/or replace the rear

shock absorbers in case of malfunction

Tyres deflated or damaged Check the correct pressure of the tyres and the

condition of the tread. Inflate to the correct pres-

sure or replace.

Loosen the anchorage points of the front and/or

rear suspension unit.

Heavy steering

Check the tightness between the frame, swinging
arm and engine and the fixing of the wheels to the

hub and/or the axle. Check the correct tightening

of the steering ring nut.

STEERING HARDENING

Possible Cause Operation

Torque not conforming Check the tightening of the top and bottom ring

nuts.

If irregularities continue in turning the steering

even after making the above adjustments, check

the seats in which the ball bearings rotate: replace

if they are recessed.

Excessive steering play

EXCESSIVE STEERING CLEARANCE

Possible Cause Operation

EXCESSIVE STEERING CLEARANCE Check the tightening of the top and bottom ring

nuts.

If irregularities continue in turning the steering

even after making the above adjustments, check

the seats in which the ball bearings rotate: replace

if they are recessed.

Noisy suspension

NOISY SUSPENSION

Possible Cause Operation

Components of the front suspension damaged. Check the quiet operation in the compression or

release phases of the fork and if necessary over-

haul it. Check that there is no noise or seizing

during the wheel rotation; if there is, change the

wheel bearing.

Components of the rear suspension damaged. Check the absence of noise in the compression or

release of the suspension, if necessary check the

proper tightness to the swinging arm unit and the

TROUBL - 5

Troubleshooting NRG Power Purejet

Possible Cause Operation

absence of rust or replace the entire shock ab-

sorber. Check that there is no noise or seizing

during the wheel rotation; if there is noise or seiz-

ing overhaul the final reduction assembly.

Suspension oil leakage

OIL LEAKAGE FROM SUSPENSION

Possible Cause Operation

Shock absorbers malfunctioning Replace the complete shock absorption unit

Hydraulic cartridge in the fork damaged. Replace the hydraulic cartridge

TROUBL - 6

INDEX OF TOPICS

ELECTRICAL SYSTEM ELE SYS

Electrical system NRG Power Purejet

1. Blinker switch device

2. Front left indicator with lamp

3. Horn button

4. Turn indicator selector.

5. High/low beam selector.

6. Rear brake stop button

7. Complete headlight

8. 2 lamps for parking light 12V-3W

9. Lamp for dipped beam light 12V - 35W

10.Lamp for high beam light 12V - 35W

11.Instrument unit

12.Rpm-timing sensor

13.Front brake stop button

ELE SYS - 2

NRG Power Purejet Electrical system

14.Start button

15.Front right indicator with lamp

16.Key switch

17.Fuel warning light transmitter

18.Oil mix lamp control

19.Voltage regulator

20.H.T. coil

21.Pick-up

22.Magneto

23.Starter motor

24.Front right indicator with lamp

25.Complete resistance

26.Battery 12V-9A

27.Fuse 20A

28.Fuse 5A

29.Petrol injector

30.Air injector

31.Water temperature sensor

32.Throttle body sensor

33.Output for diagnostics

34.Complete taillight

35.Rear left indicator with lamp

36.Starter relay

37.Electronic cpu

38.Fuel pump

39.Horn

Conceptual diagrams

ELE SYS - 3

Electrical system NRG Power Purejet

Ignition

IGNITION

Specification Desc./Quantity

1 Battery 12V - 9Ah
2 Fuse 20A
3 Key switch contacts
4 Voltage regulator
5 Ignition spark plug
6 HV coil
7 Flywheel magneto
8 Pick - up
9 CPU

ELE SYS - 4

NRG Power Purejet Electrical system

Headlights and automatic starter section

LIGHTS AND TURN INDICATORS

Specification Desc./Quantity

1 Flywheel magneto
2 High beam bulb Type: H8

Power: 12V - 35W

Quantity: 1

3 Digital instrument unit
4 Voltage regulator
5 Low beam bulb Type: H8

Power: 12V - 35W

Quantity: 1

6 Fuse 20A

ELE SYS - 5

Electrical system NRG Power Purejet

Specification Desc./Quantity

7 Key switch contacts
8 Battery 12V - 9Ah
9 Front parking light Type: All glass

Power: 12V - 3W

Quantity: 2

10 Turn indicator control device
11 Fuse 5A
12 Turn signal switch
13 4 turn indicator lamps 12V-10w

Battery recharge and starting

ELE SYS - 6

NRG Power Purejet Electrical system

BATTERY CHARGER AND STARTING

Specification Desc./Quantity

1 Flywheel magneto
2 Rear light with LED
3 CPU
4 Voltage regulator
5 Starter motor
6 Fuse 20A
7 Key switch contacts
8 Battery 12V - 9Ah
9 Starter remote control
10 Starter button
11 Fuse 5A
12 Fuse 5A
13 Diode
14 Two brake light buttons
15 Mixture oil level sender
16 Resistor 47 Ohm 25W

Level indicators and enable signals section

ELE SYS - 7

Electrical system NRG Power Purejet

CONSENSUSES AND LEVEL INDICATORS

Specification Desc./Quantity

1 Battery 12V - 9Ah
2 CPU
3 Fuse 20A
4 Key switch contacts
5 Water temperature sensor
6 Fuel level sending unit
7 Fuse 5A
8 Mixture oil level sender
9 Digital instrument unit
10 Wheel rpm sensor

Digital instrument panel

INSTRUMENT UNIT CONNECTOR

Specification Desc./Quantity

1 + Battery
2 + permanent power supply
3 Earth
4 Grounding for phonic wheel
5 Power supply to phonic wheel
6 Phonic wheel signal
7 Instrument light and parking light indicator
8 Instrument temperature mass
9 Not connected
10 Rpm indicator signal
11 Instrument temperature signal
12 Fuel level sensor
13 High-beam warning light
14 + Right direction indicator
15 + Left direction indicator
16 Low-oil warning light
17 Low-fuel warning light
18 Oil light check outlet
19 Injection warning light
20 Not connected

Checks and inspections

ELE SYS - 8

NRG Power Purejet Electrical system

Battery recharge circuit

The recharge circuit has a three phase generator with permanent magneto.
The generator is directly connected to the voltage regulator. The voltage regulator is connected directly
to the earth and battery positive passing through the 15A protection fuse. Therefore this system does
not have a connection to the key switch. The three phase generator provides a significant recharge
power and at low rpm, a good compromise is obtained between distributed power and idle stability.

Stator check

Disconnect the connector from the voltage regu­lator and check for continuity between each yellow
wire with the other two.
Ohm value: 0.7 - 0.9 Ohm.
Also check that each yellow wire is isolated from
the ground.
If non-conforming values are found, repeat the
checks on the stator; if incorrect values continue
to occur, replace the stator or repair the wiring.

Voltage regulator check

With the battery perfectly charged and the lights
off, measure the voltage at the battery leads with
the engine running at high rpm.
The voltage must not exceed 15.2 volts.
If higher voltages are found, replace the regulator.
If voltages under 14 volts are found, carry out the
checks for the stator and related wiring.

ELE SYS - 9

Electrical system NRG Power Purejet

Recharge system voltage check

Connect an ammeter induction clamp to the volt­age regulator positive cable. Measure the battery
voltage and turn on the lights with the engine off
and wait until the voltage settles at around 12 volts.
Start the engine and measure the current distrib­uted by the circuit with the lights on and engine at
high rpm.
If the current value is less than 10A, repeat the test
using a new regulator and/or stator instead.

Starter motor

Specifications

- Rated voltage 12V.

- Rated power 0.25 kW.

- Left rotation viewed from pinion side.

- Connection to engine with pinion and crown
wheel on transmission side crankshaft.

- Control with button

Tests to perform to check the electrical starter
Static test

Remove the left side panel.
Check the resistance of the induced brush unit.
Reference value: < or equal to 1 Ohm

- Use a lift to adequately support the vehicle.

- Remove the stand and support.

- Use a multimeter to check the continuity of the
positive and negative power supply cable.

- Make sure the connections are good.
If no faults are found, replace the starter.

Specific tooling

020331Y Digital multimeter

ELE SYS - 10

NRG Power Purejet Electrical system

Dynamic tests

Check the battery voltage after it has not been
used for a few hours.
Voltage < or equal to 12.5 V.
Check the density of the electrolyte of each ele­ment.
Bé = 30 ÷ 32
Specific weight: 1.25 ÷ 1.26
Make sure the negative terminals (battery nega­tive and starter negative) are correctly connected
to each other and to the frame.

- Connect the diagnostic tester.

- Connect an ammeter induction clamp to the neg­ative power supply cable of the starter.

- Disconnect the fuel injection connector.

- Turn to «ON».

- Select the «PARAMETERS» function.

- Start the engine (making sure the vehicle cannot
move) long enough to measure the rpm and starter
absorption.

- Absorption at drag rpm: from 15 to 25A.

- Drag rpm: from 500 to 550 rpm

N.B.

THE VALUE OF DECLARED RPM IS THAT IN­DICATED BY THE DIAGNOSTIC TESTER

Specific tooling

020460Y Scooter diagnosis and tester

Carry out a no-load absorption test.
Remove the transmission cover.
Remove the starter pinion.

ELE SYS - 11

Electrical system NRG Power Purejet

With the starter motor in no-load, maximum absorption must be 10 A with power supply voltage ≥ 12V.

STARTER MOTOR

Specification Desc./Quantity

Starter motor

Voltmeter

Starter motor contactor

Start button

Battery 12V-9Ah

Ammeter

See also

Centre-stand
Side fairings

Turn signals system check

The turn signal circuit is managed by an intermit­tent device.
If there is a fault in the turn signal circuit check:

- The 5A fuse indicated in the photo by removing
the air duct.

- Use a multimeter to check if there is + 12V voltage
on the BLUE-BLACK wire to the turn signal con­nector.

ELE SYS - 12

NRG Power Purejet Electrical system

- To make sure the lamps work, apply a +12V volt­age to the WHITE-BLUE wire of the turn indicator
switch for the right lamps and to the PINK wire for
the left lamps.

See also

Air duct

level indicators

Composed of the petrol level transmitter, analogue
reading instrument and reserve warning lamp.
In the event of a fault check:

- Fuel reserve warning lamp

- The 5A fuse indicated in the photo by removing
the air duct.

- Make sure the voltage at the WHITE wire of the instrument unit is +12V

- Using a multimeter check the ohm values of the fuel level by moving the arm with float.
Limit values:
empty tank position = 87 - 103 Ohm
½ tank position = 34 - 42 Ohm
full tank position < or equal to 7 Ohm

See also

Air duct

The oil mix lamp carries out a timed check for 3
seconds every time the key is switched to ON. The
check is controlled by the turn indicator device
which applies a 12V voltage to the oil warning
lamp.
If the check is not carried out when the key is
switched to ON, check:

- If the lamp is working

- The 5A fuse indicated in the photo by removing
the air duct.

- Use a multimeter to check if there is 12V voltage at the 2 YELLOW oil mix lamp control wires when
the key is turned to ON

- The oil mix lamp is working

ELE SYS - 13

Electrical system NRG Power Purejet

To access the oil mix lamp control remove the right panel. Remember that the +12V voltage to the 2
YELLOW oil mix lamp control lasts 3 minutes from when the key is switched to ON.

See also

Air duct
Side fairings

Lights list

The lighting system goes on when the key is
switched to ON.
The high beams can be selected using the high
beam/dipped beam selector.
If faults occur in the lighting system check:

- If the lamps are working

- The 5A fuse indicated in the figure by removing
the air duct.

- Use a multimeter the make sure there is + 12V voltage at the GREY - RED wire of the cover with
contacts

- That at the YELLOW - BLACK wires of the light there is a + 12V voltage

- Make sure the lamp holder earth is present.

See also

Air duct

Sealed battery

Airtight battery start-up operations

INSTRUCTIONS FOR REFRESHING THE STOCK CHARGE OF AN OPEN CIRCUIT

1) Voltage check

Before installing the battery on the vehicle, check the open circuit voltage with a normal tester.

- If the voltage exceeds 12.60 V, the battery may be installed without any renewal recharge.

- If voltage is below 12.60 V, a renewal recharge is required as explained in 2).

2) Constant voltage battery charge mode

-Constant voltage equal to 14.40÷14.70V

-Initial charge voltage equal to 0.3÷0.5 for nominal capacity

-Duration of the charge: 10 to 12 h recommended
Minimum 6 h
Maximum 24 h

3) Constant current battery charge mode

-Charge current equal to 1/10 of the nominal capacity of the battery

-Duration of the charge: 5 h

ELE SYS - 14

NRG Power Purejet Electrical system

WARNING

-WHEN THE BATTERY IS REALLY FLAT (WELL BELOW 12.6V) IT MIGHT BE THAT 5 HOURS OF
RECHARGING ARE NOT ENOUGH TO ACHIEVE OPTIMAL PERFORMANCE.
IN THESE CONDITIONS IT IS HOWEVER ESSENTIAL NOT TO EXCEED EIGHT HOURS OF CON­TINUOUS RECHARGING SO AS NOT TO DAMAGE THE BATTERY ITSELF.

Dry-charge battery

WARNING

THE BATTERY ELECTROLYTE IS POISONOUS AS IT MAY CAUSE SERIOUS BURNS. IT CON­TAINS SULPHURIC ACID. AVOID CONTACT WITH THE EYES, THE SKIN AND CLOTHING. IF
COMING INTO CONTACT WITH EYES OR SKIN, WASH ABUNDANTLY WITH WATER FOR AP­PROX. 15 MIN. AND SEEK IMMEDIATE MEDICAL ATTENTION.
IN THE EVENT OF ACCIDENTAL INGESTION OF THE LIQUID, IMMEDIATELY DRINK LARGE
QUANTITIES OF WATER OR MILK, MAGNESIUM MILK, BATTERED EGG OR VEGETABLE OIL.
SEEK IMMEDIATE MEDICAL ATTENTION.
THE BATTERIES PRODUCE EXPLOSIVE GAS; KEEP CLEAR OF NAKED FLAMES, SPARKS OR
CIGARETTES; VENTILATE THE AREA WHEN RECHARGING INDOORS.
ALWAYS WEAR EYE PROTECTION WHEN WORKING IN THE PROXIMITY OF BATTERIES.
KEEP OUT OF REACH OF CHILDREN

Characteristic

Battery

12V-9Ah

Commissioning dry-charge batteries:

1) Once the short closed tube and caps are removed, add sulphuric acid to the elements, of a type for
batteries with a specific gravity of 1.26, corresponding to 30° Bé at a temperature of at least 15°C until
reaching the upper level.

2) Let it sit for two hours.

3) Use the specific battery charger (single or multiple) to charge to an intensity equal to around 1/10 of
the capacity until the voltage has reached a value of around 2.7 V per element. The density of the acid
should be about 1.27, corresponding to 31° Bé, and the values have stabilised. The duration of the
charging operations must be 15 - 20 hours.

4) Once the charging is complete, level out the acid (add distilled water or remove excess acid), put
on the caps and clean carefully.

5) Once these operations have been completed, install the battery on the vehicle, correctly following
the connections described in point 3) «Battery charging».

WARNING

- ONCE THE BATTERY HAS BEEN INSTALLED IN THE VEHICLE IT IS NECESSARY TO REPLACE
THE SHORT TUBE (WITH CLOSED END) NEAR THE + POSITIVE TERMINAL WITH THE CORRE­SPONDING LONG TUBE (WITH OPEN END), THAT YOU FIND FITTED TO THE VEHICLE, TO
ENSURE THAT THE GASES THAT FORM CAN ESCAPE PROPERLY.

Specific tooling

020333Y Single battery charger
020334Y Multiple battery charger

ELE SYS - 15

Electrical system NRG Power Purejet

Battery maintenance

The battery is the electric device that requires the
most careful monitoring and diligent maintenance.
The maintenance rules are:

1) Check the level of the electrolyte

Check regularly that the electrolyte level is at up­per level. Use only distilled water to top up the
level.
If the battery needs topping up very frequently,
check the vehicle electrics: the battery is probably
working in overload conditions which will lead to
rapid deterioration.

2) Check the charge

After topping up the electrolyte, check the density
using a densimeter (see figure).

CHECKING ELECTROLYTE DENSITY

Specification Desc./Quantity

Keep the tube vertical

Check with bare eye

The float must be released

When the battery is charged, the density should be 30 ÷ 32 Bé corresponding to a specific weight of

1.26 ÷ 1.28 at a temperature not under 15° C.
If the density falls below 20° Bé, the battery is completely run down and needs to be recharged. When
a battery is being charged the voltage of each element must be 2.6 ÷ 2.8V.
The discharge limit of each element is 1.8V.
When charging is completed, check the level and density of the electrolyte as well as the voltage of
each element. If the vehicle is not used for long periods of time (1 month or longer) the battery must be
periodically recharged.
The battery will completely discharge over three months. When the battery is refitted onto the vehicle,
be careful not to invert the connections: remember that the ground wire (black) needs to be connected
to the negative (-) terminal, while the red wire is connected to the terminal marked with the positive

(+) sign.

3) Recharging the battery

WARNING

BEFORE RECHARGING THE BATTERY, REMOVE THE CAPS OF EACH CELL.
KEEP THE BATTERY AWAY FROM NAKED FLAMES OR SPARKS WHILE IT IS CHARGED.
FIRST DETACH THE NEGATIVE LEAD BEFORE REMOVING THE BATTERY FROM THE VEHICLE.

Normal charging on the bench is done with the specific battery charger (single or multiple), positioning
the battery charger selector on the type of battery to recharge at a current of 0.9A for around 6 ÷ 8

ELE SYS - 16

NRG Power Purejet Electrical system

hours. The connections with the power supply source must be made by connecting the corresponding
poles (+ with + and - with -). The battery caps must be removed during charging.

Specific tooling

020333Y Single battery charger
020334Y Multiple battery charger

4) Cleaning the battery

The battery should always be kept clean, especially the upper part, and the terminals protected with
vaseline.

CAUTION

NEVER USE FUSES WITH A CAPACITY HIGHER THAN THE RECOMMENDED CAPACITY. USING
A FUSE OF UNSUITABLE RATING MAY SERIOUSLY DAMAGE THE VEHICLE OR EVEN CAUSE
A FIRE.

CAUTION

IN EMERGENCIES, THE CHARGING TIME CAN BE DECREASED TO 5-6 HOURS.

CAUTION

ORDINARY AND DRINKING WATER CONTAINS MINERAL SALTS THAT ARE HARMFUL FOR
THE BATTERY. FOR THIS REASON, YOU MUST ONLY USE DISTILLED WATER.

CAUTION

CHARGE THE BATTERY BEFORE USE TO ENSURE OPTIMUM PERFORMANCE. INADEQUATE
CHARGING OF THE BATTERY WITH A LOW LEVEL OF ELECTROLYTE BEFORE IT IS FIRST
USED SHORTENS THE LIFE OF THE BATTERY.

ELE SYS - 17

Electrical system NRG Power Purejet

ELE SYS - 18

INDEX OF TOPICS

ENGINE FROM VEHICLE ENG VE

Engine from vehicle NRG Power Purejet

Removal of the engine from the vehicle

1. Detach the battery.

2. Remove the exhaust assy.

3. Remove the rear wheel.

4. Remove the rear brake cable.

5. Detach the electrical connection to the fly­wheel.

6. Detach the throttle and mixer cables.

7. Detach the mixture oil, fuel, and vacuum
pump outlet tubing.

8. Detach the H.T. cable from the spark plug.

9. Remove the rear shock-absorber fixing bolt
from the engine.

10.Remove the nut on the l.h.s., and hence re­move the engine - swing-arm fixing bolt.

Locking torques (N*m)

Engine-swinging arm bolt 33 ÷ 41 Shock ab­sorber-engine pin 33 to 41 Nm Rear wheel axle
nut 104 ÷ 126

ENG VE - 2

INDEX OF TOPICS

ENGINE ENG

Engine NRG Power Purejet

Automatic transmission

Transmission cover

- Loosen the 15 screws and remove the transmis-

sion cover with the aid of a mallet.

N.B.

THE CRANKCASE IS SLIGHTLY BLOCKED BY
THE TIGHT FIT BETWEEN THE SHAFT OF THE
DRIVEN HALF-PULLEY AND THE BEARING
HOUSED ON THE CRANKCASE.

Air duct

- Remove the Radiator grill

- Remove the air conveyor by disengaging the

special joints

See also

Front central cover

Removing the driven pulley shaft bearing

- Slightly heat the crankshaft from the inside side

to avoid damaging the coated surface and use the
driven pulley shaft or a pin of the same diameter
to remove the bearing.

N.B.

IN CASE OF DIFFICULTY A STANDARD 8MM­INSIDE DIAMETER EXTRACTOR CAN BE
USED.

ENG - 2

NRG Power Purejet Engine

Refitting the driven pulley shaft bearing

-Refit the bearing with the aid of a bushing with the same diameter as the external plate of the bearing
after slightly heating the crankcase from the inside.

N.B.

WHEN REFITTING, ALWAYS REPLACE THE BEARING WITH A NEW ONE.

CAUTION

WHEN REMOVING/REFITTING THE BEARING, TAKE CARE NOT TO DAMAGE THE PAINTED
SURFACE.

Removing the driven pulley

- Lock the clutch bell housing with the specific tool.

- Remove the nut, the clutch bell housing and the
whole of the driven pulley assembly.

N.B.

THE UNIT CAN ALSO BE REMOVED WITH THE
DRIVE PULLEY MOUNTED.

Specific tooling

020565Y Flywheel lock calliper spanner

Inspecting the clutch drum

- Check that the clutch bell is not worn or damaged.

- Measure the inner diameter of the clutch bell.

Characteristic

Clutch bell diameter/standard value

Ø 107+0.2 +0 mm

Clutch bell diameter/max. value allowed after
use

Ø 107.5 mm

Eccentricity measured /max.

0.20 mm

ENG - 3

Engine NRG Power Purejet

Removing the clutch

- Equip the tool with long pins screwed into position

«A» from the outside, insert the entire driven pulley
in the tool and put the central screw under stress.

CAUTION

THE TOOL WILL BE DEFORMED IF THE CEN­TRAL SCREW IS TIGHTENED UP TOO FAR.

- Using a 34 mm socket wrench remove the clutch

locking nut.

- Loosen the central screw thereby undoing the

driven pulley unit

- Separate the components.

Specific tooling

020444Y Tool for fitting/ removing the driven
pulley clutch

Inspecting the clutch

- Check the thickness of the clutch mass friction

material.

- The masses must not show traces of lubricants;

otherwise, check the driven pulley unit seals.

N.B.

UPON RUNNING-IN, THE MASSES MUST EX­HIBIT A CENTRAL CONTACT SURFACE AND
MUST NOT BE DIFFERENT FROM ONE AN­OTHER.
VARIOUS CONDITIONS CAN CAUSE THE
CLUTCH TO TEAR.

CAUTION

DO NOT OPEN THE MASSES USING TOOLS
TO PREVENT A VARIATION IN THE RETURN
SPRING LOAD.

Characteristic

Check minimum thickness

1 mm

ENG - 4

NRG Power Purejet Engine

Pin retaining collar

- Remove the collar with the aid of 2 screwdrivers.

- Remove the three guide pins and the mobile half
pulley.

Removing the driven half-pulley bearing

- Remove the roller bearing with the special ex­tractor inserted from the bottom of the fixed half­pulley.

CAUTION

POSITION THE HOLDING EDGE OF THE EX­TRACTION PLIERS BETWEEN THE END OF
THE BEARING AND THE BUILT IN SEALING
RING.

Specific tooling

001467Y029 Bell for bearings, O.D. 38 mm

- Remove the ball bearing retention snap ring.

- Expel the ball bearing from the side of the clutch
housing by means of the special tool.

N.B.

PROPERLY SUPPORT THE HALF-PULLEY SO
AS NOT TO DEFORM THE SLIDING SURFACE
OF THE DRIVING BELT

Specific tooling

020376Y Adaptor handle
020363Y 20 mm guide

ENG - 5

Engine NRG Power Purejet

Inspecting the driven fixed half-pulley

- Check that there are no signs of wear on the work

surface of the belt. If there are, replace the half­pulley..

- Make sure the bearings do not show signs of un-

usual wear.

- Measure the external diameter of the pulley bush-

ing.

Characteristic

Stationary driven half-pulley/Standard diame­ter

Ø 33.965 to 33.985 mm

Stationary driven half-pulley / Minimum diam­eter admitted after use

Ø 33.96 mm

Inspecting the driven sliding half-pulley

- Remove the 2 inner sealing rings and the two O-

rings.

- Measure the inside diameter of the mobile half-

pulley bushing.

Characteristic

Mobile driven half-pulley/ Maximum diameter
allowed

Ø 34.08 mm

- Check the belt contact surfaces.

- Insert the new oil seal and O-rings on the mobile

half-pulley.

- Fitting the half-pulley on the bushing.

Recommended products

AGIP GREASE SM 2 Grease for the tone wheel
revolving ring

Soap-based lithium grease containing NLGI 2 Mo­lybdenum disulphide; ISO-L-XBCHB2, DIN
KF2K-20

- Make sure the pins and collar are not worn, reassemble the pins and collar.

ENG - 6

NRG Power Purejet Engine

- Use a greaser with a curved spout to lubricate the driven pulley unit with around 6 gr. of grease. This
operation must be done through one of the holes inside the bushing until grease comes out of the
opposite hole. This procedure is necessary to prevent the presence of grease beyond the O-ring.

Recommended products

AGIP GREASE SM 2 Grease for the tone wheel revolving ring

Soap-based lithium grease containing NLGI 2 Molybdenum disulphide; ISO-L-XBCHB2, DIN KF2K-20

Refitting the driven half-pulley bearing

- Fit a new ball bearing with the specific tool.

- Fit the ball bearing retention snap ring.

- Fit the new roller bearing with the wording visible
from the outside.

CAUTION

PROPERLY SUPPORT THE HALF-PULLEY TO
PREVENT DAMAGE TO THE THREADED END
WHILE THE BEARINGS ARE BEING FITTED.

Specific tooling

020376Y Adaptor handle
020456Y Ø 24 mm adaptor
020362Y 12 mm guide
020171Y Punch for Ø 17 mm roller case

Refitting the driven pulley

• Check the surfaces contacting with the belt.

• Insert the new oil seals and the O-rings on the
mobile half-pulley.

• Fit the half-pulley on the bushing.

CAUTION

WHILE FITTING THE MOBILE DRIVEN HALF­PULLEY, TAKE CARE NOT TO DAMAGE THE
OIL SEALS.

• Check that pins and collar are not worn, refit pins and collar.

• Use a bent tip oiler to lubricate the pulley unit with approx. 6 gr grease. This operation must be per­formed through one of the holes into the bushing until the grease starts leaking from the opposite hole.
This procedure is necessary to prevent the presence of grease beyond the O-ring.

Recommended products

AGIP GREASE SM 2 Grease for odometer transmission gear case

Lithium grease with NLGI 2 Molybdenum disulphide; ISO-L-XBCHB2, DIN KF2K-20

ENG - 7

Engine NRG Power Purejet

• Measure the free length of the mobile driving half-

pulley.

Characteristic

Standard length:

110 mm

Inspecting the clutch spring

- Check that the contrast spring of the driven pulley

does not show signs of deformation

- Measure the free length of the spring

Characteristic

Standard length

118 mm

Minimum length allowed after use

XXXX

Refitting the clutch

- Preassemble the driven pulley group with spring,

sheath and clutch.

- Position the spring with the sheath

- Insert the components in the tool and preload the

spring being careful not to damage the plastic
sheath and the end of the threaded bar.

- Reassemble the nut securing the clutch and tight-

en to the prescribed torque.

CAUTION

SO AS NOT TO DAMAGE THE CLUTCH NUT
USE A SOCKET WRENCH WITH SMALL
CHAMFER.

CAUTION

POSITION THE NON-CHAMFERED SURFACES
OF THE NUT IN CONTACT WITH THE CLUTCH

Locking torques (N*m)

ENG - 8

NRG Power Purejet Engine

Nut locking clutch unit on pulley 55 ÷ 60 Nm

Refitting the driven pulley

• Refit the driven pulley assembly, the clutch bell
and the nut using the specific tool.

Specific tooling

020565Y Flywheel lock calliper spanner

Locking torques (N*m)

Locking torque: 40 ÷ 44 N·m

Drive-belt

- Make sure the driving belt is not damaged and
does not have cracks in the toothed grooves.

- Check the width of the belt.

Characteristic

Transmission belt/Minimum width

17.5 mm

Removing the driving pulley

- Lock the driving pulley using the appropriate tool.

- Remove the central nut with the related washer,
then remove the drive and the plastic fan.

- Remove the stationary half-pulley.

- Remove the belt, washer and remove the mobile half-pulley with its bushing, being careful that the
rollers and contrast plate fitted loosely on it do not come off.

Specific tooling

020451Y Start-up crown lock

ENG - 9

Engine NRG Power Purejet

Inspecting the rollers case

1) Check that the bushing and the sliding rings of

the mobile pulley do not show signs of scoring or
deformation.

2) Check the roller running tracks on the contact

pulley; there must not be signs of wear and check
the condition of the contact surface of the belt on
the half-pulleys (mobile and stationary).

3) Check that the rollers do not show signs of

marked facetting on the sliding surface and that
the metallic insert does not come out of the plastic
shell borders.

4) Check the integrity of the sliding blocks of the

contact plate.

- Check that the internal bushing shown in the fig-

ure is not abnormally worn and measure inside
diameter «A».

- Measure outside diameter «B» of the pulley slid-

ing bushing shown in the figure.

CAUTION

DO NOT LUBRICATE OR CLEAN THE BUSH­ING.

Characteristic

Driving pulley / Maximum diameter:

20.12 mm

Driving pulley/ Standard diameter:

20.021 mm

Driving pulley bushing/ Diameter maximum:

XXX mm

Driving pulley bushing/ Standard diameter:

20 -0.020/-0.041mm

ENG - 10

NRG Power Purejet Engine

Refitting the driving pulley

- Manually move the mobile driven half-pulley
away pulling it towards the clutch unit and insert
the belt repeating the direction of rotation of the
first fitting.

N.B.

IT IS GOOD PRACTICE ALWAYS TO FIT THE
BELT SO THE WORDING CAN BE READ, IN
THE CASE THAT THIS DOES NOT SHOW A
FITTING SIDE.

- Refit the particular components of the assembly
(roller container assembly with bushing, limiting
washer, stationery half-pulley, cooling fan belt with
drive, washer and nut).

- Tighten the lock nut to torque 20 Nm and then
perform a final 90° lock preventing the rotation of
the drive pulley with the specific tooling.

N.B.

REPLACE THE NUT WITH A NEW ONE AT EV­ERY REFIT

CAUTION

IT IS MOST IMPORTANT WHEN FITTING THE
DRIVING PULLEY UNIT THAT THE BELT IS
FREE INSIDE IN ORDER TO AVOID MAKING A
WRONG TIGHTENING WITH THE POSSIBLE
LATER DAMAGE OF THE CRANKSHAFT
KNURLING.

Specific tooling

020451Y Start-up crown lock

Locking torques (N*m)

Crankshaft pulley nut 18 to 20 + 90° N.m

End gear

ENG - 11

Engine NRG Power Purejet

Removing the hub cover

• Remove the transmission cover

• Remove the clutch assembly

• Discharge the rear hub oil.

• Remove the 5 screws indicated in the figure.

• Remove the hub cover with driven pulley shaft.

See also

Refitting the clutch

Removing the wheel axle

- Remove the intermediate gear and the complete

gear wheel axle.

- When removing the intermediate gear pay atten-

tion to the various shim adjustments.

Removing the wheel axle bearings

- Remove the oil seal and the seeger ring.

- Remove the bearing by pushing from the outside

towards the inside of the gear compartment, using
the appropriate punch.

Specific tooling

020363Y 20 mm guide
020376Y Adaptor handle
020358Y 37x40-mm adaptor

ENG - 12

NRG Power Purejet Engine

Removing the driven pulley shaft bearing

- Remove the seeger ring inside the cover.

- Remove the oil seal from the outside.

- Remove the centring dowels and position the
cover on a plane.

- Position the special tool on the internal track of
the bearing and remove said bearing with the aid
of a press.

Specific tooling

020452Y Tube for removing and refitting the
driven pulley shaft

- Position the special tube on the internal raceway
of the bearing and from the shaft toothed side as
indicated in the figure. Expel the driven pulley shaft
with the aid of a press.

Specific tooling

020452Y Tube for removing and refitting the
driven pulley shaft

Inspecting the hub shaft

- Check that the three shafts exhibit no wear or
deformation on the toothed surfaces, at the bear­ing housings and at the oil guards.

- In case of anomalies, replace the damaged com­ponents.

- Check that the fitting surface is not dented or dis­torted.

- If faults are found, replace the hub cover.

ENG - 13

Engine NRG Power Purejet

Refitting the driven pulley shaft bearing

- Support the inner track of the bearing from the

outside of the hub cover with the specific tool posi­tioned under the press and insert the driven pulley
axle.

- Refit the oil seal flush with the cover.

Specific tooling

020452Y Tube for removing and refitting the
driven pulley shaft

• Heat the hub cover and insert the bearing with

the specific punch.

• Fit the snap ring with the concave or radial part

on the bearing side.

N.B.

FIT THE BALL BEARING WITH THE SHIELD
FACING THE OIL SEAL.

Specific tooling

020151Y Air heater
020376Y Adaptor handle
020439Y 17 mm guide
020358Y 37x40-mm adaptor

Refitting the wheel axle bearing

- Heat the half crankcase on the transmission side

using a thermal gun.

- After lubricating its outer strip, insert the bearing

with the special adapter with the aid of a hammer.

- Refit the seeger ring and the oil seal using the 42

x 47 mm adapter and the handle.

Specific tooling

020151Y Air heater
020376Y Adaptor handle
020363Y 20 mm guide
020359Y 42x47-mm adaptor

ENG - 14

NRG Power Purejet Engine

Refitting the ub cover

• Refit the complete wheel axis.

• Refit the intermediate gear being careful of the
two shim adjustments.

• Apply LOCTITE 510 for surfaces on the hub cov­er and refit it with the complete pulley shaft.

• Insert the 5 screws and tighten them to the pre­scribed torque.

N.B.

CLEAN THE CONTACT SURFACES OF THE
HUB COVER AND THE HALF CRANKCASE OF
RESIDUE FROM PREVIOUS GASKETS BE­FORE APPLYING A NEW ONE.

Locking torques (N*m)

Locking torque: 11 to 13 Nm

Flywheel cover

Removing the stator

- Remove the flywheel cover.

• Use a specific compass wrench and a 15 mm
Allen wrench to remove the flywheel lock-nut.

Specific tooling

020565Y Flywheel lock calliper spanner

ENG - 15

Engine NRG Power Purejet

• Use a specific extractor to remove the flywheel

Specific tooling

020162Y Flywheel extractor

• Remove the two studs of the revolutions sensor

to the coolant inlet pipe.

• Remove the coolant inlet duct

• Remove the two stator fixing screws

• Remove the stator with wiring and revolution

sensor

Locking torques (N*m)

Flywheel nut 40 to 44 N.m

Refitting the stator

- To refit, perform the removal procedures in the reverse direction.

ENG - 16

NRG Power Purejet Engine

Refitting the flywheel cover

•

Fit the rubber seal on the flywheel con­nector and around the inlet coolant
hose.

•

Keeping the flywheel connector rubber
clamp on the coolant inlet hose, refit
the flywheel cover paying attention in
inserting the strap in the groove.

•

Tighten the 4 studs, noting that the two
longer golden screws are inserted in
the 2 top holes and are also responsi­ble for restraining the secondary air­box.

Cylinder assy. and timing system

• Remove the flywheel cover using the 4 screws
shown in the figure.

ENG - 17

Engine NRG Power Purejet

Removing the cylinder head

• Use a TORX 20 wrench to remove the air feeding

line from the injection head as shown in the figure.

• Remove the injection head, including the fuel in-

jector and the pressure regulator, using the 2
screws shown in the figure

• Remove the spark plug

• Remove the temperature sensor shown in the

figure

To remove the air injector, extract the dust cover
and use a screwdriver to remove the injector as
shown in the figure

N.B.

BE CAREFUL NOT TO DAMAGE THE INJEC­TOR PLASTIC SUPPORT

ENG - 18

NRG Power Purejet Engine

• Remove the coolant outlet union from the head
with the relevant O-ring, using the two screws, as
shown in the figure.

• Remove the head inside recirculation duct as
shown in the figure.

• Remove the head using the 4 screws as shown
in the figure.

ENG - 19

Engine NRG Power Purejet

Removing the cylinder - piston assy.

• Remove the cylinder holding the piston in order

to prevent damage

• Remove the 2 plug stops by a screwdriver inser-

ted into the special slits on the piston

• Remove piston pin and remove the piston

N.B.

USE PAPER OR A CLOTH TO CLOSE THE CYL­INDER HOUSING MOUTH ON THE CRANK­CASE TO PREVENT SLIPPAGE OF ONE OF
THE PIN LOCKING RINGS INTO THE CASE.

• Remove the roller from the connecting rod as

shown in the figure

• Remove the piston sealing rings

CAUTION

NOTE THE ASSEMBLY POSITIONS OF THE
LININGS TO PREVENT INVERTING THE POSI­TION IN CASE OF REUSE.

N.B.

BE CAREFUL NOT TO DAMAGE THE SEALING
RINGS DURING REMOVAL.

ENG - 20

NRG Power Purejet Engine

Inspecting the small end

- Measure the internal diameter of the small end
using an internal micrometer.

N.B.

IF THE DIAMETER OF THE ROD SMALL END
EXCEEDS THE MAXIMUM DIAMETER AL­LOWED, SHOWS SIGNS OF WEAR OR OVER­HEATING REPLACE THE CRANKSHAFT AS
DESCRIBED IN THE "CRANKCASE AND
CRANKSHAFT" CHAPTER".

Characteristic

Rod small end: standard diameter

17 +0.011-0.001

Rod small end: maximum allowable diameter

17,060 mm

Inspecting the wrist pin

- Check the wrist pin external diameter using a mi­crometer

Characteristic

Wrist pin: standard diameter

12 +0.005 +0.001 mm

Inspecting the piston

- Measure the bearings on the piston using a bore
meter

- Calculate the piston-pin coupling clearance.

Characteristic

Wrist pin housing: standard diameter

12 +0.007 +0.012

Wrist pin housing: standard clearance

0.002 ÷ 0.011 mm

ENG - 21

Engine NRG Power Purejet

- Measure the outer diameter of the piston, per-

pendicular to the pin axis.

- Take the measurement in the position shown in

the figure
To classify the cylinder-piston fitting, check the ap­propriate table

See also

Cylinder - piston assy.

Inspecting the cylinder

• Check that the cylinder exhibits no seizure. If it

does, replace or adjust it, while respecting the al­lowable oversizes.

• Use a bore meter to measure the cylinder inside

diameter according to the directions shown in the
figure.

• Check that the fitting surface with the head is not worn or deformed
To classify the fitting, refer to the tables.

See also

Cylinder - piston assy.

Inspecting the piston rings

• Alternatively, insert the 2 sealing rings into the

cylinder.

• Insert the rings in an orthogonal position relative

to the cylinder axis, using the piston.

• Measure the sealing ring opening by a feeler

gauge, as shown in the figure.

• If the values are higher than those prescribed on the chart, replace the rings

ENG - 22

NRG Power Purejet Engine

Removing the piston

• Insert the roller in the connecting rod

• Fit piston and wrist pin on the connecting rod, with
piston facing the outlet

• Insert the wrist pin stop ring in the specific tool
with the aperture in the position shown on the tool,
as in the figure

• Place the wrist pin stop ring into position using a
punch

Specific tooling

020166Y Pin lock fitting tool

ENG - 23

Engine NRG Power Purejet

• Fit the wrist pin stop using the plug as shown in

the figure

Specific tooling

020166Y Pin lock fitting tool

Choosing the gasket

• Temporarily fit the cylinder on the piston, without

the basic gasket.

• Fit a dial gauge on the specific tool, using the

short union as shown in the figure.

Use a reference plane to reset the dial gauge with
a pre-load of a few millimetres.
Set the dial gauge.
Check that tracer slides smoothly.
Fit the tool on the cylinder without changing the
dial gauge position.
Lock the tool by the nuts used to secure the head.

Turn the engine shaft to the dead centre position (dial gauge rotation inversion point).
Measure the difference with the reset value.
Refer to the table to identify the thickness of the cylinder base gasket to use for refitting. The correct
identification of the thickness of the cylinder base gasket allows maintaining the correct compression
ratio.
Remove the specific tool and the cylinder.

Specific tooling

020272Y Piston position check tool

See also

Cylinder - piston assy.

ENG - 24

NRG Power Purejet Engine

Refitting the head and timing system components

• Carefully clean the head, removing any carbon
residues

• Check the perfect condition of the fitting surfaces

• Check that the O-rings are not broken, otherwise
replace them

• Screw the 4 head fixing nuts and tighten them in
crossed sequence to the prescribed torque

Locking torques (N*m)

Head fixing nuts: 10 ÷11 Nm

• Refit the head inside recirculation duct as shown
in the figure.

• Check that the O-Ring is in good working condi­tion.

• Fit the coolant outlet union on the head with rel­evant O-ring by tightening 2 screws to the prescri­bed torque.

Locking torques (N*m)

Coolant outlet union fixing screws: 3 ÷ 4 Nm

• Introduce the air injector into the head.

ENG - 25

Engine NRG Power Purejet

• Refit the dust cover onto the air injector.

N.B.

NOTE THAN WHEN THE AIR INJECTOR IS RE­FITTED, THE CARBON DAM O-RING MUST BE
NEW. IF A NEW AIR INJECTOR IS FITTED, THE
NEW CARBON DAM RING IS ALREADY
PRESENT. IF THE OLD AIR INJECTOR IS FIT­TED, THE CARBON DAM REQUIRES RE­PLACEMENT.

• Fit the spark plug

• Refit the temperature sensor shown in the figure

and tighten to the prescribed torque.

Locking torques (N*m)

Temperature sensor 18 ÷22 Nm Spark plug: 11
÷ 14 Nm

• Refit the injection head including the fuel injector

and pressure regulator and tighten to the prescri­bed torque.

Locking torques (N*m)

Injection head fixing screw: 3 ÷ 4 Nm

• Use a TORX 20 wrench to refit the air feeding

pipe from the injection head.

See also

air injector circuit

Air Injection

Carbon - dam replacement

ENG - 26

NRG Power Purejet Engine

- Remove the air injector

- The carbon dam ring must be broken to be re­moved.

- Carefully clean the air injector and the seat re­moving any carbon residues.

- Check that the sealing rings exhibit no wear, or
replace them.

- To refit, use a new carbon dam ring.

- Use the specific tool to fit the carbon dam ring.
We recommend doing this in several steps to en­sure a correct widening of the ring as shown in the
photo.

Specific tooling

020615Y Carbon dam ring fitting kit

- Position the specific tool with the rung facing the
injector as shown in the figure.

- Use the specific tool to tighten the carbon dam
ring seat as shown in the figure.

- Take several steps to ensure a correct insertion
into the seat.

- Refit the air injector in its seat on the head quickly
to prevent the carbon dam ring from expanding
again.

Specific tooling

020615Y Carbon dam ring fitting kit

Crankcase - crankshaft

• Remove flywheel and stator

- Remove the driving pulley

- Remove the driven pulley

- Remove the mixer

ENG - 27

Engine NRG Power Purejet

- Remove the throttle body with manifold, diaphragm, gasket and blade support

- Remove the volumetric compressor

- Remove the thermal unit

- Remove the starter

See also

Removing the driven pulley
Removing the driving pulley
Cylinder assy. and timing system
Removal

Splitting the crankcase halves

- Remove the 8 crankcase half clamping screws

shown in the figure

- Insert the guard on the crankshaft as shown in

the figure.

- Use the specific tool to remove the crankcase half

on the flywheel side. Place the tool being careful
to correctly centre it

- Use a 17 mm Allen wrench to remove the crank-

case half on the flywheel side.

N.B.

IF SEPARATION REQUIRES FORCING, USE A
THERMAL GUN TO HEAT THE CRANKCASE IN
THE BENCH BEARING ZONE

Specific tooling

020151Y Air heater
020163Y Crankcase splitting plate

ENG - 28

NRG Power Purejet Engine

- Install the specific tool with relevant guard on the
transmission side crankcase half. Use four M6
screws of a suitable length.

- Use a 17 mm Allen wrench to remove the crank­shaft from the transmission side crankcase half.

Removing the crankshaft

- Install the specific tool on the half crankcase on
the transmission side using four M6 screws of an
adequate length.

- Remove the crankshaft from the transmission
side half crankcase

Specific tooling

020163Y Crankcase splitting plate

Removing the crankshaft bearings

- Bearings may be left on the crankcase halves or
on the crankshaft.

- Use the specific tool to remove any bearings left
on the crankshaft.

N.B.

HALF-RINGS MUST BE INSERTED ON THE
BEARINGS BY STRIKING THEM WITH A MAL­LET.

Specific tooling

004499Y Camshaft bearing extractor
004499Y007 Half rings

ENG - 29

Engine NRG Power Purejet

- Use the specific tool to remove any bearings left

on both crankcase halves.

Specific tooling

001467Y006 Pliers to extract 20 mm bearings
001467Y007 Driver for OD 54 mm bearing

Refitting the crankshaft bearings

- This operation requires assembly by temperature

- Dip the bearings in oil bath when this is still cold.

Avoid contact between bearings and container.

- Use an appropriate amount of oil (approx.1 l)

- Gradually heat the container with a thermal gun

until the oil temperature reaches approx. 150°.

- Check the temperature using a multimeter provi-

ded with thermal probe

N.B.

IF THE BEARINGS WERE IMMERSED INTO
HOT OIL, THEY WOULD BE IMMEDIATELY
DAMAGED.

- Place the crankshaft on the special support

- Alternately introduce the 2 bearings to insert

them home.

- If required, use a specific pipe to ensure their in-

sertion.

N.B.

THIS OPERATION SHOULD BE PERFORMED
QUICKLY AND WITH PRECISE MOVES. OTH­ERWISE, START OVER.

Specific tooling

020265Y Bearing fitting base

ENG - 30

NRG Power Purejet Engine

008119Y009 Tube to assemble shafts and
axles

Inspecting the crankshaft components

- Check for any abnormal wear on the eccentric
track.

- To check using the dial gauge, see the section
«Checking crankshaft alignment»

Inspecting the crankshaft alignment

With the specific tool shown check that the eccen­tricity of the surfaces of diam. «A»-«B»-« C» are
within 0.03 mm. (reading limit on the dial gauge);
in addition, check the eccentricity of diam. «D», for
which a maximum reading of 0.02 mm is permitted.
In the case where eccentricity is not much above
prescribed levels, straighten the shaft by acting
on the counterweights with a shim or tighten them
in a clamp (with an aluminium bushing) as re­quired..

Specific tooling

020335Y Magnetic support for dial gauge
020074Y Support base for checking crankshaft

alignment

ENG - 31

Engine NRG Power Purejet

Inspecting the crankcase halves

- Remove the oil seals from both crankcase halves

using a screwdriver.

- Clean the fitting surfaces removing Loctite resi-

dues and residues of the paper seal on the cylin­der.

- For this operation, use specific products available

on the market. Avoid any method that may impair
the crankcase fitting surfaces.

- To facilitate this operation, remove the rotor.

Please note that the threading is anticlockwise.

- Check the fitting surfaces and the bearing and oil

seal capacities.

- Check the cleaning and efficiency of the unidir-

ectional valve of the oil supply to the pump case.

- Check the correct installation of the reference

dowels.

ENG - 32

NRG Power Purejet Engine

Refitting the crankshaft

- Place the transmission side crankcase half on
two wooden supports.

- Refit the water pump rotor (note that the thread­ing is anticlockwise)

- Use the thermal gun to heat the bearing seat to
approx. 120°.

N.B.

MAKE SURE THAT THERE IS THE NECESSA­RY SPACE IN THE LOWER SIDE TO INSERT
THE CRANKSHAFT.

- Insert the crankshaft using a firm movement until
the bearing reaches home.

N.B.

CHECK THAT THE CONNECTING ROD IS
PLACED ACCORDING TO THE CYLINDER AX­IS. IF ASSEMBLY IS UNSUCCESSFUL, START
OVER FOLLOWING THE HEATING RULES
AND BEING CAREFUL TO THE SHAFT INSER­TION MOVEMENT. DO NOT LUBRICATE THE
SHAFT SINCE THE CRANKCASE HALF FIT­TING SURFACES MAY BE SOILED.

- Let the crankcase half temperature settle with the
crankshaft temperature.

- Install the specific crankcase separation plate
again without installing the crankshaft guard.

- Keep the central thrust screw loosened during
assembly.

- Move the 4 fixing screws to the end of stroke and
loosen them again by the same angle (e.g. 90°)

- When temperature has settled, pre-load the
thrust screw of the tool manually until the bearing
ball backlash is zeroed.

N.B.

AN EXCESSIVE PRE-LOAD MAY CHANGE THE
CRANKCASE BEARING POSITION.

ENG - 33

Engine NRG Power Purejet

- Prepare the fitting surface using the recommen-

ded product applying a thin layer after degreasing
the surface with a suitable solvent (e.g. trichloro­ethylene)

Recommended products

Loctite 510 Liquid sealant

Gasket

- Assemble the equipment need to close the crank-

case half (screws, wrench).

- Heat the crankcase half on the flywheel side us-

ing the thermal gun, with the same procedure on
the transmission side crankcase half.

- Keep the transmission side crankcase half in hor-

izontal position to introduce the flywheel side
crankcase half with a firm and precise move.

N.B.

WEAR GLOVES WHEN HANDLING THE
CRANKCASE HALF. DO NOT USE RAGS FOR
THIS OPERATION.

- Insert at least 3 fixing screws and tighten quickly.

- Insert 5 more screws and tighten at the prescribed torque.

Locking torques (N*m)

Crankcase closing screws: 12 -13 Nm

ENG - 34

NRG Power Purejet Engine

Refitting the crankcase halves

- Prepare the coupling surface with LOCTITE 510
applying a thin layer of it after degreasing the sur­face using a suitable solvent (e.g. trichloroethy­lene)

- Heat the flywheel-side half crankcase with a ther­mal gun.

Recommended products

Loctite 510 Liquid sealant

Gasket

- Keeping the half crankcase on the transmission
side, insert the flywheel side half crankcase with a
clean precise movement

- Insert at least three clamping screws and tighten
up rapidly

- Insert the other 5 screws and tighten them to the
specified torque.

Locking torques (N*m)

crankcase coupling screws 11 - 13

- Move the crankcase separation plate in a position
back from the one indicated in the figure

- Install the special magnetic support with dial
gauge at the end of the crankshaft

- Check the axial clearance of the crankcase
If this is not within the maximum limit allowed, re­peat the crankcase coupling procedure

Specific tooling

020335Y Magnetic support for dial gauge

Characteristic

Axial clearance with warm crankcase

0.10 ÷ 0.12 mm

Axial clearance with cold crankcase

0.06 to 0.08 mm

Limit value with cold crankcase

0.02 ÷ 0.03 mm

ENG - 35

Engine NRG Power Purejet

Air compressor

Removal

Air compressor removal

- Remove the throttle body manifold

- Remove the air piping union from the injection

head using a Torx 25mm wrench

- Remove the air piping support bracket fixing

screw from the transmission covers.

- Remove the 4 screws fixing the air compressor

to the crankcase, as shown in the figure.

- Remove the air compressor

ENG - 36