2005 NCK Local Option Class
NCK National Cup 125cc TaG

For the 2006 race season, this class have been replaced by 125cc National Cup Light and 125cc National Cup Heavy.  Click here, to go to the 2006 class menu page.

These supplemental rules are intended to work in conjunction with the IKF rules in general, and the IKF 2-cycle rules in particular.  In the event of a conflict between any of these supplemental rules and any of the IKF general or 2-cycle rules, these supplemental rules will control.

1.

Clarification - 125cc national cup class since its inception by Northern California Track Association has its own set of rules.  I.K.F. Leopard rules and I.K.F. T.A.G. rules are not a part of, nor apply to 125cc National Cup Rules & Specs.
 

2.

Class Specifications 125cc national cup class since its inception by Northern California Track Association has its own set of rules.  I.K.F. Leopard rules and I.K.F. T.A.G. rules are not a part of, nor apply to 125cc National Cup Rules & Specs.

3.

Chassis Specifications

3.1

As per section 200 Sprint Racing.

3.1.1

55" maximum width.

3.1.2

C.I.K. style bodywork is required (2002 or 2003 and newer).
 

4.

Tires

4.1

Yokohama YO1 - 4.50 front / 7.10 rear.

4.1.1

No doping of tires.  Tires may not appear wet or sticky at any time.  Subject to immediate DQ.
 

5.

General

5.1

No carbon / carbon or fiber braking systems.

5.2

Airboxes are required, and shall have a maximum of two 22mm tubes, see technical specifications section 6.8.

5.3

Catch containers are required for radiator overflows.

5.4

Cooling systems may use only water or water-based coolants.

5.5

Radiator must be OEM.

5.6

Batteries must be gel cell type and sealed.  (No cracks or leaks).

5.7

Stalled karts may restart using electric starter, but the driver must remain in the kart.
 

6.

Technical Specifications

6.1

Unless otherwise specified, ALL components of the airbox, carburetor, carburetor cup, engine (ALL internal and external parts of the engine), reed cage, starter, ignition, clutch, header, pipe and radiator shall be OEM and as Original Manufacture (see section 504.3 IKF Rules), AND must meet specifications.  NO after market parts or parts other than Original Manufacture are allowed except as specified in section 6.

6.2

NO Blue printing, realigning, grinding, reshaping, sandblasting, polishing, coating, removal or addition of ANY material on ALL components of the carburetor, carburetor cup, engine (ALL internal and external parts of the engine), reeds and reed cage, starter, ignition, clutch, header, pipe, except as specified in section 6.
 

6.3

Cylinder

6.3.1

One or more shims may be placed under the cylinder to adjust the port degree timing to meet specifications.

6.3.2

Material may be removed from the top edge only of the cylinder to meet minimum head volume cc specifications.

6.3.3

The cylinder may be bored and / or honed to fit OEM pistons and rings as normal maintenance requires.  NO radius of port windows or other areas of cylinder are allowed.  Cylinder may not exceed maximum bore specifications.
 

6.4

Head

6.4.1

Material may be removed from the bottom of the head to meet minimum head volume cc specifications of 9.5cc with I.K.F.  2-cycle CC measuring plug (LAD tool) see I.K.F. Technical Inspection Manual Sec. 602.1.4.

6.4.2

Head combustion chamber may be reshaped, but must meet minimum head volume CC specifications as noted above in 6.4.1.

6.4.3

Checking head volume, refer to I.K.F. Technical Inspection Manual section 602.1. with the exception that the desired displacement in section 602.1.5 for the burette calibration tool shall be 9.5cc.
 

6.5

Clutch

6.5.1

No alteration of the clutch from known manufacturer's stock parts.  Any attempt to bypass or circumvent this rule will be considered illegal.

6.5.2

The clutch body shall have a minimum weight of 460 grams.  This will not include hardware or mounting parts.

6.5.3

The clutch drum shall have a minimum weight of 292 grams.  This will not include the drive gear, hardware or mounting parts.
 

6.6

Carburetor

6.6.1

Tillotson 334A or 334AB 23mm Maximum bore carburetors are legal and allowed.

6.6.2

Carburetor may be mounted in either up or down position.

6.6.3

Air filter cup must be OEM, as Original Manufacture, no machining allowed.

6.6.4

See I.K.F. Technical Inspection Manual section 603.1.3.

6.6.5

Fuel mixture screws may have extensions added to assist in carb tuning.

6.6.6

Throttle shaft screw is non-tech, but must be in place.

6.6.7

No installation of O-rings or other sealing devices on carb shaft.

6.6.8

No machining of carb body (sec.6.2) except carburetor gasket plates may be surfaced to a flat condition without excessive removal of material.

6.6.9

Throttle linkage cable clamp is non-tech.

6.6.10

Throttle linkage is non-tech.

6.6.11

Pulse hole no go is 0.101 inches.
 

6.7

Reeds

6.7.1

Reeds must meet minimum thickness of 0.30mm ± 0.05mm.
 

6.8

Airbox

6.8.1

Must have a maximum of two 22mm baffles plus or minus 1mm.  Each baffle not to exceed 23mm (.905") in diameter and 95mm (3.74") minimum length.

6.8.1.1

Air box tech gauge, refer to I.K.F. Technical Inspection Manual section 603.1.4.5.

6.8.2

Internal or external air cleaners are legal.

6.8.3

Rubber mounting flange may be used in straight or angled position.
 

6.9

Spark Plug

6.9.1

The only allowable spark plugs are NGK BR10EG or NGK BR9EG.

6.9.2

The spark plug must be a ¾" reach plug.  Refer to I.K.F. Technical Inspection Manual section 602.1.4.

6.9.3

The spark plug boot is non-tech.
 

7.

Technical Inspection

7.1

Exhaust Port Duration Check

7.1.1

Mount a degree wheel on the crankshaft of the engine.

7.1.2

Place a .008 (.2mm) feeler gauge between the piston and the top of the exhaust port.  Roll the piston up by the crankshaft until the .008 feeler gauge is gently contacted between the piston and the top of the exhaust port.

7.1.3

Set the degree wheel to zero.  Leaving the .008 feeler gauge in place begin rotating the crankshaft so that the piston moves downward.

7.1.4

Pass bottom dead center and continue to move the piston back up the cylinder until you bump the .008 feeler gauge.

7.1.5

Now read the degree wheel.

7.1.6

The BM 120cc engine should not exceed 173 degrees.

7.1.7

The Parilla 125cc engine should not exceed 171 degrees.