Idaho Speedway Kart & Engine Rules

All Officiating and Race Results are performed by each race tracks officials.

All Karts must be able to pass Pre-Race Safety tech before being allowed on the track.

Engine Rules are posted below the Driver & Kart Rules

UAS Class Rulebook - http://www.unlimitedallstars.org/rules.html

Driver & Kart Safety Tech (All Classes):

Pit:

Fire extinguisher and First Aid kit are highly recommended.

Driver:

- Helmet must be Snell 2015 or newer

- Gloves are mandatory

- Neck Collar is mandatory

- Closed toed shoes are mandatory

- Long Sleeve Jacket and long pants are minimum requirement. Kart racing jacket or suit recommended.

Kart:

- All bolt-on weight must be white in color. Kart number posted in black.

- All weight added to meet minimum kart/driver weight requirements shall be bolted and safety wired to the kart with a minimum 5/16-inch or 8mm bolt, with weight over 5 pounds requiring two bolts. Double nuts are permitted but threads must protrude.

- Weight mounted to the seat must use a large 1 1/4" washer to prevent the head of the bolt from pulling through the seat.

- Carrying of ballast on the driver’s person is prohibited.

- No weight may be mounted to the underside of the chassis.

- Seats must be fiber glass, carbon, or plastic. No aluminum or Cage Kart style seats allowed. 

The following connections must be safety wired / pinned / clipped / double nutted during any session:

- Pedal (brake and throttle)

- All brake rods and safety tether

- Master cylinder to frame

- Wolf Plate must be installed if applicable

- Calipers to frame/spindle

- Kingpins

- Steering shaft to frame

- Tie Rods (all mounting points)

- Steering hub to steering shaft

- Steering wheel to steering hub

- Wheel hub to front Spindle

Pre-Race Technical Inspection:

- Inspect driver’s helmet for proper certification

- Inspect frame for cracks and defects. Noticeable cracks and defect will render the chassis unfit for competition and will need to be replaced or welded. If welded, it must get the approval of the Race Director to continue.

- Verify brakes will lock when reasonable pressure is applied to the pedal.

- Verify Wolf plate is in place and mounted properly if applicable.

- Verify throttle fully closes when throttle pedal is released.

- Verify all safety items are lock nutted and/or wired.

- Verify weights are white with kart number posted in black and properly mounted.

- Verify front spindles are safety wired and/or clipped.

- Verify nerf bars, bumpers, and bodywork are properly secured.

- Verify all exhaust is properly secured.

- Verify all fuel system components are free of defect, and fuel line is properly 

secured to attachment points.

- Verify cameras are hard mounted to bodywork.

The registered driver must submit their kart and helmet to the Pre-Race tech Inspection official(s) prior to taking to the track for any session. Additionally, each entrant is obligated to ensure that their kart(s) maintain all general safety measures (including personal safety equipment) for the duration of the sanctioned event. 

Any kart failing Pre-Race Technical Inspection has the opportunity to correct any / all problems as pointed out by the officials and re-submit the entry for approval.

Decisions of the Race Director and Chief Technical Inspector concerning Pre-Race tech may not be protested.

Jr II 4-Cycle

Min weight - 265 lbs

Sealed Briggs Lo206 or Sealed Predator Ghost

Chain guard is mandatory 

Sr4 Animal Engine

Min weight - 360 lbs

Briggs & Stratton Animal Engines Rules

Air Filter - Any aftermarket air filter allowed

Header / Muffler - Any aftermarket header pipe allowed - 24" max - Can not extend past rear bumper. Muffler optional, no sharp edges.

Carburetor - BS# 555658 Only - .794 x .615 max venturi - Gasoline only.

Camshaft - Any stock lift cam .257 max lift

Piston - OEM or Burris only .035 oversize max (2.725)

Rod - Billet rod allowed

Block - Decking block is allowed 

Head - Valve seats 45* angle only. 

Milling head gasket surface is allowed.

Head Gasket - OEM only .042 min thickness

Valves - Stock only, 45* angle only

Spark Plug, fasteners, and clutch are non tech

Chain guard is mandatory

Sr4 Clone Engine

(Honda Gx200, Clone, Predator)

Min weight - 360 lbs

Air Filter - Any aftermarket air filter allowed

Header / Muffler - Any aftermarket header allowed. Muffler is optional, must be safety wired - 24" max - Can not extend past rear bumper

Carburetor - Stock Appearing - .615 max bore - Gasoline only 

Cam - Any stock lift cam .231 max 

Piston - OEM gx200, OEM 196cc Clone or OEM Honda only - 68mm (2.680) - .030 max oversize 

 Predator engines OEM only - 70mm (2.760) - No oversize pistons allowed

Rod - Billet rod allowed

Block - Decking the block is allowed

Head - OEM Honda Gx200, OEM Clone or OEM Predator only - Any single valve springs allowed - Milling head gasket surface and porting allowed - No oversize valves

Head Gasket - OEM or Honda only - .010 min thickness - Hemi engines .040 min thickness - multi layer gaskets allowed

Valves - OEM valve size only - 45* angle only - Stainless valves / Aluminum keepers allowed

Flywheel - PVL or Billet flywheel only

Top Plate, Fuel Pump, Throttle Linkage allowed

Spark plug, fasteners, clutch are non tech items

Chain guard is mandatory

Limited Mod - Stage 2/3

(212cc Max - Clone / Briggs)

Min weight - 360 lbs

Block - Cast Blocks Only 

Head - Cast heads only - Big Valve heads allowed

Flywheel - PVL or Billet flywheel only 

Header / Muffler - Any aftermarket header allowed. Muffler is optional, exhaust trumpet or RLV B91MO, must be safety wired, 24" max - Can not extend past rear bumper.

Chain guard is mandatory.

ISK Pre Race Tech sheet are available for download below.