Gas gas EC 200, EC 250, EC 300 WORKSHOP MANUAL

WORKSHOP MANUAL /

WORKSHOP MANUAL /

WERKSTATTHANDBUCH

WERKSTATTHANDBUCH

MOTOR EC Enducross

MOTOR EC Enducross

200 / 250 / 300

200 / 250 / 300

INTRODUCTION

This manual was created by GAS GAS Motos, S.A. for the use of official GAS GAS services. It is principally
directed at operators with a basic knowledge of the principles of mechanics and repair techniques. It contains
precise instructions for making all the repairs, in addition to the necessary technical data to carry out the
maintenance of the motorbikes.

There is also considerable information about the special GAS GAS tools and equipment that will be of great
help in optimising repair processes.

In successive editions, we will keep you informed of all the updates and evolution of the motorbikes in this
family.

Particularly important information in the manual is preceded by one of the following symbols.

i

GAS GAS Motos, S.A

Note: indicates points of particular interest for more efficient and convenient operation.

Warning: indicates special instructions or procedures which should be followed to the letter

!

to avoid damaging the equipment.

Danger: indicates special instructions or procedures which must be followed to the letter to

!

avoid physical injury to the operators.

I

CONTENTS

CONTENTS

Sect. P.

Sect. P.

IV GENERAL INFORMATION

IV GENERAL INFORMATION

VI TABLE OF TECHNICAL DATA

VI TABLE OF TECHNICAL DATA

01 01 REMOVING THE ENGINE FROM THE CHASSIS

01 01 REMOVING THE ENGINE FROM THE CHASSIS

02 01 FITTING THE ENGINE ON THE CHASSIS

02 01 FITTING THE ENGINE ON THE CHASSIS

03 01 DISMOUNTING ENGINE

03 01 DISMOUNTING ENGINE

04 01 SERVICE AND REPAIR OF THE ENGINE COMPONENTS

04 01 SERVICE AND REPAIR OF THE ENGINE COMPONENTS

05 01 ASSEMBLING THE ENGINE

05 01 ASSEMBLING THE ENGINE

06 01 ELECTRICAL SCHEMAS

III

GENERAL INFORMATION

Certain safety and maintenance norms should be remembered when carrying out repairs to the vehicles. Some
of the more important norms are listed below:

Safety

- Do not smoke or cause sparks or naked flames in the work area. Petrol is highly inflammable and may be
explosive in certain conditions.

- Use cleaning products appropriate to each task, ensuring that they have been approved.

- Always wear protective eye equipment when using electric tools such as drills, sanders or grinders.

- Apply a protective hand cream before commencing dismantling work. This protects the skin from infection
and makes subsequent cleaning easier. Ensure that hands are not slippery.

- Remember that prolonged contact of the skin with engine oil can be damaging to health.

- Keep loose clothing away from moving parts.

- Do not wear rings, wristwatches, etc while working on the engine, especially the electrical system.

- Keep the work area tidy, it is easy to trip over elements left on the floor.

- Avoid leaving oils, grease or other fluids on the floor of the work area to avoid slipping on them.

- Use suitable tools for compressing or decompressing springs to prevent these from escaping suddenly.

- Take special care not to inhale dust from parts containing asbestos (for example: clutch discs), this product
is extremely dangerous for your health.

- Avoid inhaling fumes from petrol or cleaning fluids, these can be highly toxic. Ensure that the work area is
well-ventilated.

Maintenance

- Always use original GAS GAS spare parts and lubricants recommended by the manufacturer. Other spare
parts may damage the engine.

- Only use the tools specified for this vehicle.

- Always replace all the gaskets, seals and O-rings during service and assembly.

- After dismounting, clean components with non-inflammable dissolvent.

- Lubricate all work surfaces before assembly, except the conical couplings.

- Oil all the paired parts and bearings when assembling.

- When removing, servicing and assembling parts, only use metric-sized tools. Metric screws, nuts and bolts
are not interchangeable with parts with Imperial measurements.

- All the surfaces receiving gaskets, seals and O-rings must be carefully cleaned.

- Carefully examine all the circlips before assembly and replace any which are damaged. Always replace the
piston pin circlip after each use.

- After assembly check all the components are correctly fitted and the mechanisms are working perfectly.

IV

General tightening torques

The following table specifies tightening torques for nuts or bolts with ISO threads.
Tightening torques for components or special units are given in the relevant repair process described in this
manual.
To avoid damage, tighten units with various nuts or bolts progressively and in diagonal or alternate pairs, until
obtaining the specified torque.
To apply the tightening torques described below, clean, dry threads are necessary. Components should be at
room temperature.

*(A) NUT

10 mm
12 mm
14 mm
17 mm
19 mm
22 mm

*A: Distance between the nut faces.
*B: External diameter of screw thread.

Engine serial number

The engine serial number is stamped on the lower part of the left crankcase.

*(B) BOLT

6 mm

8 mm
10 mm
12 mm
14 mm
26 mm

GENERAL TIGHTENING TORQUES

Nm

6
15
30
55
85

130

Kgf.m

0,6
1,5
3,0
5,5
8,5

13,0

Ft.lb

4,3

11
22
40
61
94

Remember to quote the engine serial number each time you place an order for an original GAS GAS spare
part for said engine.

V

TABLE OF TECHNICAL DATA

Engine
Definition Mono-cylindrical 2-stroke engine, liquid-cooled, intake to crankcase
Displacement in cubic centimetres 200 Engine: 199.4cc

250 Engine: 249.3cc
300 Engine: 294.7cc

Fuel RON / SUPER-LEAD-FREE 95-98 octane.

Mixed with SYNTHETIC 2T oil

Mixture ratio 100% synthetic oil: petrol 50: oil 1 (2%)
Petrol / oil semi-synthetic oil: petrol 40: oil 1 (2.5 %)
Bore and stroke 200 Engine: 62.5 x 65 mm

250 Engine: 66.4 x 72 mm

300 Engine: 72 x 72 mm

Spark plug NGK BR8EG
Electrode separation 0.7 - 0.8 mm
Ignition timing 1 mm BTDC
Piston rings: quantity 2 rings
Starter system Kick-start pedal

System Liquid-cooled, with impulse pump
Circuit capacity 1.1 litres
Mix ratio Distilled water: 50%

Antifreeze: 50 %

System Carburetion
Carburettor KEIHIN PWK 38
Fuel tank 9 litres
Fuel supply Gravity
Air filter Dry air filter

Ignition system CDI system
Voltage / Power 12 V / 110 W

Transmission 6-speed cascade
Clutch Oil bath, multi-disk hydraulic action
Secondary transmission By chain
Gear ratio

1st gear 2.071 (29/14)
2nd gear 1.625 (26/16)
3rd gear 1.333 (24/18)
4th gear 1.100 (22/20)
5th gear 0.913 (21/23)
6th gear 0.791 (19/24)

Primary reduction ratio 200 cc: 3.22 (58/18); 250 - 300 cc: 2.85 (57/20)
Final reduction ratio 3.615 (47/13)
Overall drive ratio (6

th

gear) 200 cc: 9.21; 250 - 300 cc: 8.149
Oil type 10W30 API SF or SG
Oil capacity 900 cc

VI

Engine

200 cc / 250 cc / 300 cc

EC ENDUCROSS WORKSHOP MANUAL

Ed: 07/05

REMOVING THE ENGINE FROM THE CHASSIS

Note:
The cylinder head, the cylinder, the clutch and

i

- Thoroughly clean the motorcycle before starting to dismantle
the engine.

- Place the motorcycle on a support suitable for work.

- Remove the seat.

- Dismantle the plastic covers on both sides.

- Remove the fuel tank.

the ignition, can be removed without
dismounting the engine from the chassis.

01-01

- Remove the lever from the kick-start pedal - arrow-.

- Release the springs holding the exhaust pipe to the cylinder
pipe.

Engine

200 cc / 250 cc / 300 cc

EC ENDUCROSS WORKSHOP MANUAL

01-02

REMOVING THE ENGINE FROM THE CHASSIS

- Remove the whole exhaust system.

Note:

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- Remove the drain plug -arrow- and drain the transmission
oil.

The oil must never be poured down the drain
or into the environment.

Danger:
Make sure that the coolant fluid is not hot
before opening the coolant circuit.

!

Ed: 07/05

Note:

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- Remove the radiator cap.

- Unscrew the coolant drain plug in the water pump and allow
the fluid to drain into the containert.

- Clean any fluid which falls on the engine, chassis or wheels.

- Disconnect the spark plug connector -1- and disconnect the
coolant pipes on both sides of the engine.

- Remove the back brake pedal and the back brake pump
guard, setting them to one side.

Place the coolant in a clean container, it may
be reused later.

Engine

200 cc / 250 cc / 300 cc

EC ENDUCROSS WORKSHOP MANUAL

Ed: 07/05

REMOVING THE ENGINE FROM THE CHASSIS

- Undo the screws -arrows-, remove the chain pinion and the
hydraulic clutch calliper with the gasket.

- Loosen the chain.

- Extract the clutch rod -arrow- entirely.

1

Note:
The position of the chain pinion before

i

removing. It should be replaced in the same
position to ensure the same direction of wear.

01-03

2

- Remove the circlip -1- of the chain pinion using circlip pliers.

- Remove the chain pinion -2- from the secondary shaft.

- Remove the gear lever.

- Release the magnetic flywheel wiring from its fastening on
the chassis; disconnect the connector on the control unit
(CDI) and the remaining wiring connectors.

- Remove the carburettor.

Engine

200 cc / 250 cc / 300 cc

EC ENDUCROSS WORKSHOP MANUAL

01-04

REMOVING THE ENGINE FROM THE CHASSIS

- Remove the screws -arrows- fastening the engine to the
chassis.

- Loosen the screw fastening the cylinder head support to
the chassis.

- Remove the screw -arrow- fastening the engine to the lower
chassis.

- Remove the nut -1-, remove swing arm and move backwards.

1

- Position the engine ready for removal and then take off.

Ed: 07/05

Engine

200 cc / 250 cc / 300 cc

EC ENDUCROSS WORKSHOP MANUAL

Ed: 07/05

B

A

FITTING THE ENGINE ON THE CHASSIS

- Fit the engine on the chassis and correctly position on the
supports.

- Line up swing arm with the engine and chassis, grease
swing arm and fit.

- Place engine fastening screws in supports.

Note:
The self-locking fastening nuts of the engine
must be replaced with new nuts.

C

D

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- Tighten all the nuts slightly and then to the specified torque:

Nuts Tightening torque

A 38 to 48 Nm
B 24 to 29 Nm
C 38 to 48 Nm
D 66 Nm

02-01

- Assemble the carburettor.

- Place the magnetic flywheel on the chassis and fasten
correctly.

- Connect the control unit connector and the remaining wiring
connectors.

- Assemble the gear lever.
Tightening torque: 15 Nm

Note:
The chain pinion must be fitted in the same

i

position as when it was removed to ensure
the same direction of wear.

Engine

200 cc / 250 cc / 300 cc

EC ENDUCROSS WORKSHOP MANUAL

02-02

FITTING THE ENGINE ON THE CHASSIS

- Place the chain pinion -2- on the secondary shaft and fit the
circlip -1-.

1

- Fit the clutch rod -arrow-.

2

- Fit the hydraulic clutch calliper with a new gasket, fit the
chain pinion guard and tighten screws -arrows-.
Tightening torque: 6 Nm

- Tension the chain.

- Assemble the back brake pedal and the back brake pump
guard.
Tightening torque: 29 Nm

Ed: 07/05

Note:

i

- Connect the spark plug connector -arrow- and connect the
coolant pipes on both sides of the engine.

i

Tightening torque: 9 Nm

- Disconnect the coolant recirculation pipe.

- Fill the coolant system through the left radiator cap.
Mixture of coolant and distilled water: 1:1 (antifreeze 50%,
distilled water 50%).
Capacity 1.1 litres.

i

Check that the coolant pipes are not cut or
worn.

Note:

Ensure that the coolant drain plug in the water
pump is screwed in tightly and has a new seal.

Note:
Ensure that the transmission oil drain plug is
tightened and has a new gasket.

Tightening torque: 20 Nm

Engine

200 cc / 250 cc / 300 cc

EC ENDUCROSS WORKSHOP MANUAL

Ed: 07/05

FITTING THE ENGINE ON THE CHASSIS

- Remove the oil filler cap -arrow- and fill with new transmission
oil.
Viscosity: 10W30
Capacity 900 cc

- Fit the oil filler cap with a new gasket and tighten.

- Pump the starter pedal 3 or 4 times and check the oil level
through the indicator -arrow-.

- Apply Nural 29 to the exhaust system unions.

02-03

- Fit the complete exhaust system and tighten screws slightly.

- Check the condition of the O-rings of the exhaust; if they
are deteriorated, replace them.

- Correctly fit the springs holding the exhaust pipe to the
cylinder pipe.

- Tighten the exhaust system screws.
Tightening torque: 6 Nm

Engine

200 cc / 250 cc / 300 cc

EC ENDUCROSS WORKSHOP MANUAL

02-04

FITTING THE ENGINE ON THE CHASSIS

- Fit the kick-start pedal lever, apply Loctite 243 to the screw

-arrow- and then tighten.

- Tightening torque: 20 Nm

- Fit the fuel tank and the vent hose.

- Check the condition of the air filter. If it is damaged, replace
with a new one. If it is undamaged, clean and refit (see user
manual).

- Replace the plastic covers on both sides of the motorcycle.

- Fit the seat.

Note:
After the first stage of running in, check the

i

oil and coolant levels, the chain tension and
generally inspect the engine.

Ed: 07/05

- Check no coolant is leaking from the radiator hoses.

Engine

200 cc / 250 cc / 300 cc

EC ENDUCROSS WORKSHOP MANUAL

Ed: 07/05

DISMOUNTING ENGINE

Prior instructions:

Note:
When dismounting the engine keep all the
paired parts together. This includes gears,
cylinders, pistons and other parts subject to
natural wear in pairs.
Paired components must always be replaced
together.

i

During the disassembly, clean all the parts
and place them on trays in the order they are
removed. This will accelerate assembly and
ensure the correct installation of all the parts.
Parts should be kept away from any source
of fire.
All gaskets, seals and O-rings should be
replaced whenever the engine is dismounted
partially or completely.

03-01

- Thoroughly clean engine before placing on work bench.

- Place the motor on the bench.

- Remove spark plug from cylinder head.

Dismantling the ignition

- Undo the screws -arrows- of the ignition cover.

Engine

200 cc / 250 cc / 300 cc

EC ENDUCROSS WORKSHOP MANUAL

03-02

1

DISMOUNTING ENGINE

Ed: 07/05

- Block the magnetic flywheel.

- Remove the nut -1-.

Warning:
The magnetic flywheel nut is loosened by

!

turning to the left!

- Insert the extractor ref. ME25634045 on the internal thread
of the magnetic flywheel.

- Remove the magnetic flywheel by holding the extractor with
a wrench while threading the screw.

- Remove the pin from the crankshaft.

- Undo the screws -arrows- from the ignition stator and remove
it with the wiring.

Dismantling the water pump

- Undo the screws -arrows- of the water pump cover.

Engine

200 cc / 250 cc / 300 cc

EC ENDUCROSS WORKSHOP MANUAL

Ed: 07/05

DISMOUNTING ENGINE

- Block the turbine -1- of the water pump.

- Undo the fastening screw -2- and remove the turbine from
the water pump.

2
1

- Remove the complete seal -arrow- from the water pump.

03-03

2

1

2

1

1

1
2

2

1

2

2

Removing cylinder head and cylinder

- Undo bolts -1- on the clutch disc cover and remove cover.

- Undo bolts -2- on the clutch cover and remove cover.

- Remove the clutch cover gasket.

- Undo the screws -arrows- of the exhaust valve right-hand
cover.

Engine

200 cc / 250 cc / 300 cc

EC ENDUCROSS WORKSHOP MANUAL

03-04

2

2

DISMOUNTING ENGINE

2

1

2

2

1

1

2

2

Ed: 07/05

- Remove the fastening nut -1- from the operating lever and
the nut -2- from the exhaust valve rod.

- Loosen screws -1- and remove thermostat cover.

- Loosen cylinder head screws -2- in diagonal pairs and
remove cover from cylinder.

Note:

i

- Remove inner and outer O-rings of the cylinder head.

If the cylinder head does not come off easily
hit lightly with a plastic hammer.

- Undo the screws -arrows- of the exhaust valve left-hand
cover.

- Remove the fastening nuts -arrows- from the cylinder to the
crankcase, on both sides of the engine.

- Remove the cylinder by lifting upwards.

Note:

i

- Remove the cylinder gasket.

If the cylinder does not come off easily hit
lightly with a plastic hammer.

Engine

200 cc / 250 cc / 300 cc

EC ENDUCROSS WORKSHOP MANUAL

Ed: 07/05

DISMOUNTING ENGINE

Note:

i

- Mark the orientation of the piston towards the exhaust port
using a permanent marker.

- Place a clean cloth at the base of the cylinder to prevent
the circlip from falling in the crankcase.

- Remove a circlip from the pin and take out the pin by pushing
from the opposite end.

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There may be more than one gasket.

Note:
If necessary, gently tap the pin using a suitable
tappet.

03-05

Dismantling the clutch

Note:
If the clutch is being removed in order to, for
example, replace the discs, it is not necessary

i

- Remove the screws -1- undoing in diagonal pairs.

- Remove the clutch springs and the rod bushings.

1

1

1

1

- Remove the clutch press -2-.

- Remove the set of clutch discs from the housing.

to remove the complete clutch cover. To
access the clutch discs it is only necessary
to remove the clutch disc cover.

2

1

1

Engine

200 cc / 250 cc / 300 cc

EC ENDUCROSS WORKSHOP MANUAL

03-06

1

2

DISMOUNTING ENGINE

Ed: 07/05

- Open the safety catch -1- of the fastening nut of the clutch
hub -2-.

- Loosen the nut by holding the clutch hub.

Warning:
The clutch hub nut is loosened by turning to

!

the left!

- Remove the lock washer and take out the clutch hub.

Note:
The clutch hub has an assembly position with

i

respect to the primary shaft. Mark the position
using a permanent marker on the grease ring.

- Remove the clutch housing washer.

- Remove the clutch housing.

- Remove the clutch housing bearings -1-, the bushing -2­and the washer -3-.

3

2

1