From a press release issued by the FIM:

Mies, October 4 2003

Superbike & Supersport World Championships
2004 Technical Rules – Changes

The main modifications to the Superbike & Supersport Technical Regulations for the 2004 season are the following (the full text will be available next week on the FIM Internet site):

2.4, Superbike Technical Specifications


2.4.1, Displacement capacities

2 cylinder, Over 800cc up to 1000cc, 4 stroke

3 cylinder, Over 750cc up to 1000cc, 4 stroke

4 cylinder, Over 750cc up to 1000cc, 4 stroke


2.4.2, Minimum Weights

The minimum weight will be 162 kg

A 1% tolerance will be allowed after the race. (The machine’s weight after the race may not be less than 160.38 kg)



2.4.4.1, Carburation Instruments for 1000cc 3 and 4 cylinders

Carburation instruments refers to both throttle bodies and carburettors.

The original homologated carburation instruments must be used un-modified.

The uses of optional homologated carburation instruments are not allowed.

The fuel injectors may be replaced, however they must fit without modification to the homologated throttle body.

The carburation instruments intake insulators may be modified.

Bell mouths may be altered or replaced.

Variable length intake tract devices that function while the engine is operating are not allowed, unless such a system is used on the homologated machine.

Modifications to the fuel pump and the pressure regulator are allowed.

The fuel injection management computer may be changed.

The use of flash memory (flash RAM ) is allowed.

Vacuum slides may be fixed in the open position.

Secondary throttle plates and shafts may be removed or fixed in the open position and the electronics may be disconnected or removed.


2.4.6.15, Carburettors

Variable-length carburettor/fuel injection intake tract devices that function while the engine is operating are prohibited, unless such a system is use on the homologated machine.


2.4.6.16, Fuel Injection System

The fuel injectors may be replaced, however they must fit without modification to the homologated throttle body.

Vacuum slides may be fixed in the open position.
Secondary throttle plates and shaft may be removed or fixed in the open position and the electronics may be disconnected or removed.

Variable-length carburettor/fuel injection intake tract devices that function while the engine is operating are prohibited, unless such a system is used on the homologated machine.


2.4.6.18, Engine

All engines in the Superbike class must be 4 stroke type.

The following engine components may not be altered from the homologated machine except as noted.

4 cylinder engines with a bore / stroke ratio of 1.5 to 1 or greater will be subject to an RPM limit of 14,000 RPMs. This will be controlled by an electronic device issued by the FIM.


Please note rules specific for the 1000cc multi-cylinder machines (3 & 4) will be found in the article concerning the component in question. Other than noted, components may be modified or changed as allowed the following articles.

*1000cc 3 and 4 cylinders: aftermarket or modified cam drive components are allowed, however the cam drive must be in the homologated location.


2.4.6.19, Cylinder Head

1000cc 3 and 4 cylinders:

Aftermarket or modified valves, springs, retainers and other valve train components are permitted. The original number of valves must be maintained.

A. Valve diameter, including stem, must remain as homologated.

B. Valves must be made of the same basic material as the homologated valves.

C. Valves must remain in the homologated location and at the same angle as the homologated valves.


2.4.6.22, Crankshaft

1000cc 3 and 4 cylinders:

The homologated crankshaft is allowed the following modifications:

A. Bearing surfaces may be polished or a surface treatment may be applied.

B. Balancing is allowed but only by the same method as the homologated crankshaft. (for example heavy metal i.e. Mallory metal inserts are not permitted unless they are originally specified in the homologated crankshaft.)

C. Attachment of aftermarket ignition components or sensors are permitted.

D. Balance shaft may be removed.


2.4.6.30, Transmission/Gearbox

Primary gear ratios must remain as homologated for 1000cc 3 & 4 cylinder machines.


2.4.6.31, Clutch

1000cc 3 and 4 cylinders:
Aftermarket or modified clutches (wet-type cannot be changed to dry-type) with back torque limiting capabilities are permitted. (slipper type)


2.4.6.34, Exhaust System

The noise limit for Superbikes will be 107 dB/A, with a + 3dB/A tolerance after the race.




2.5, Technical Specifications for Supersport

2.5.2, Minimum Weights

600cc 4 cylinders: 162 kg
750cc 2 cylinders: 170 kg


2.5.6.2, Front Forks

The original surfaces of the front fork tubes (stanchions, fork pipes) may be changed. Additional surface treatment is allowed.


2.5.6.24, Oil Pumps, Oil Lines and Water Pumps

The internal parts of the water pump may be changed or modified. The drive ratio may be changed. The external appearance must remain as homologated.


2.5.6.32, Clutch

Aftermarket or modified, stock-type clutch with back-torque limiting capabilities (slipper type) are allowed. The use of electro-mechanical or electro-hydraulic actuating system are not allowed.


2.5.6.35, Exhaust system

The noise limit for Supersport will be 107 dB/A.


2.9.2, Minimum Production Quantities

1) Supersport

Manufacturers producing more than 75,000 motorcycles per year must produce 1’000 units for homologation.

Manufacturers producing less than 75’000 motorcycles per year must produce 500 units for homologation.