Texoma Motor Speedway

2008
Limited Mod Rules

 

Age 11 to 16
Minimum weight #325
$18.00 entry fee includes pit pass
Purse payout and championship points will be awarded.


Drivers

  1. Drivers over 16 yrs and under 11 yrs may compete with track official approval.
  2. Must have serviceable fire extinguisher in pit.

Frames

  1. Any production or custom built go-kart frame allowed. (Quarter Midget cars OK)
  2. Must be made of steel. No aluminum or titanium material

Suspension

  1. Front and rear suspension is allowed
  2. Only (1) one shock/spring per wheel

Body

  1. Bodies are mandatory. May resemble any production or race type vehicle.
  2. Fiberglass, aluminum, or steel bodies.
  3. Wings roof or front allowed. Top wing sides must stay within 3” from outer most edge of kart No sharp edges. Top wing size 3’x3’x 16” sideboard.

Bumpers & nerf bars

  1. Front and rear bumpers required of Max. 1" O.D. tubing. Not to exceed outside tread width of tires.
  2. Bumpers and Nerf bars must have rounded or capped ends. No sharp edges.

Roll Cage & Seat Belts

  1. Minimum 4 pt roll cage mandatory. Roll cage must be securely welded or bolted to frame.
  2. Minimum 3" head clearance. No conduit cages.
  3. Cage must be constructed of steel no smaller than 3/4" O.D.
  4. Minimum 4-point seat belt. Metal racing seat is recommended.
  5. Right side cage net, right side helmet support or a helmet restraint is mandatory.

Wheels and tires

  1. Any wheel or tire allowed.
  2. Grooving allowed.

Brakes

  1. Disk type brakes mandatory on rear axle.
  2. Brakes must be capable of stopping within a safe distance.

Drive train

  1. Live axle only.
  2. Chain guards are required.
  3. Centrifugal shoe, disc clutch or belt drives allowed
  4. No wet type clutches allowed

Engine

  1. Stock Briggs & Stratton Animal maximum 206 cc plus wear/repair. Intek block OK
  1. Carburetors with a maximum venturi of .875 on any manifold.
  1. May use any stock length (3.285”) connecting rod.
  2. Camshafts must be stock lift, compression relief non-tech. (Camshaft must profile WKA/IKF) (Tech will be at the valves)
  3. Fuel pump, air cleaner and ignition timing are non-tech items.
  4. Exhaust header must have flared or washer end.

Fuel

  1. Racing gasoline or alcohol fuel OK. No performance enhancements or additives allowed. This only applies to performance enhancers, is not meant to exclude top end lubricants.
  2. Must have yellow tape on kart to indicate alcohol use. Drivers must wear fire retardant racing suit. Serviceable fire extinguisher in pit is required.

STOCK 6.5 HP ANIMAL TECH SPECIFICATIONS

All parts must be Briggs & Stratton factory production parts.

ROCKER ARMS:
Must be stock as from the factory.
Overall length 2.880" + or - .005".

CAMSHAFT LIFT:
Maximum valve lift of .255" taken directly off the valve assembly at zero valve lash. (Camshaft must profile WKA/IKF)

BALL ROCKER:
As stock from factory *.600" + or - .010" diameter.

PUSH ROD:
Stock as from factory.
*.185" - .190" diameter.
*Length 5.638" - 5.656".

 VALVE TRAIN:
Stock valves ONLY. Must be one angle. Valves may not be polished or lightened. If working area (that portion of the valve stem translating with the valve guide area) of valve stem is cleaned, no material may be removed, such as linear grooves, cross-hatching, etc.
INTAKE VALVE:
45 degrees. Intake valve minimum diameter is 1.055" - 1.065". Depth of dish in valve .99" - .119".
EXHAUST VALVE:
45 degrees. Exhaust valve minimum diameter is .935" - .945". Depth of dish is valve .084" - .104".
VALVE SPRINGS:
Stock B&S valve springs and keepers are mandatory. Springs must remain unaltered as supplied from factory.

CYLINDER HEAD:
Stock cylinder head only allowed.
Depth of head at shallow part of head .011" min. Depth at floor of head .319" min.
Depth to top of valve seat: .360" max. .335" min.

PORTS:
Must have stock configuration. No porting or modifications of any kind allowed.
Intake inlet: .918 No-Go when checking 90 degrees to stud pattern No-Go will be straight, when checking in line with stud pattern No-Go will set on floor port at bottom and stop at upper edge of port on top.
Exhaust Outlet: .980 No-Go.

DECK/PISTON CLEARANCE:
Machining of deck surface is permitted. Piston pop-up CANNOT exceed .005" above block surface in the center of the piston. When measuring piston pop-up, it should be accomplished with bar stock on a parallel with the piston wrist pin in center of the piston, and using a dial indicator check the piston pop-up in this area.

STROKE:
Stroke is 2.204" Max. Stroke is checked by pushing piston down to take up play of rod clearance. Stroke is checked from bottom dead center (BDC) to top dead center (TDC).

IGNITION:
Briggs & Stratton factory stock coils are mandatory and must be utilized in unaltered form. No slotting of mounting holes or machining of attaching bolts is permitted

FLYWHEEL:
ONLY stock flywheel is permitted.
Weight of flywheel: 4 lbs. and 8 oz. MINIMUM.

VALVE LIFTERS:
Stock lifter as supplied from factory.

PISTON:
Stock, unaltered B&S piston MANDATORY. Wrist pin hole must not be altered or relocated. Deck above top ring must not be altered. No machining is allowed on piston. Arrow must point toward flywheel.

CRANKSHAFT:
Stock factory crankshaft mandatory. Stock factory timing gear mandatory, and must be installed properly. Lightening, polishing of counter weights, addition of metal or other material is not permitted. Offset crankshafts are not permitted. After-market bearing of non self-aligning type with or without shield is permitted.
DISCLAIMER Reflect
The rules and or regulations set forth herein are designed for the orderly conduct of racing events and to establish minimum acceptable requirements for such events. The rules shall govern all entrants. NO EXPRESS OR IMPLIED WARRANTY OF SAFETY SHALL RESULT FROM PUBLICATIONS OF OR COMPLIANCE WITH THESE RULES AND OR REGULATIONS. They are intended as a guide for the conduct of the sport and are in no way a guarantee against injury or death to a participant, spectator, or official.
The race director shall be empowered to permit deviations from any of the specifications, herein, or impose any further restriction, that in his opinion do not alter the minimum acceptable requirements. NO EXPRESSED OR IMPLIED WARRANTY OF SAFETY SHALL RESULT FROM SUCH ALTERATION OF SPECIFICATIONS. Any interpretation or deviations of these rules is left to the discretion of the officials. Their discretion is final.
January 1, 2008
Texoma Motor Speedway
Wichita Falls, Texas