Idaho Speedway Karting Classes

Kid Kart:

50cc Kid Karts

Kids Ages 5-8 years old
Gas Only
Spec Gear
No Weight Rule
No Tire Rule



Jr Speedway:

Ages 8-12
Gas Only
No Tire Rule
ISK Animal with Gold Restrictor plate @ #275
Briggs LO206 with Gold Slide @ #265
*Weight rule is tentative and will be adj if necessary*




Jr UAS:

Ages 13-17
Wedge Body Mandatory (Safety).
15" Max height @ front wheel c/l from the ground.
24" Max height @ rear axle c/l from the ground.
4-Stroke 14.5 cu Max.
2-Stroke any 100cc kart based piston port engine, i.e.....
Yamaha, PRD, TKM, Comer, Komet, ect.
Must remain piston port engine, (no reeds).
#320 for both 2, & 4 stroke engine platforms.




Senior 4 Cycle:

Ages 12 & up
Treaded tires only (Effective 5/18)
ISK Animal or ISK Clone Engine @ #360
Briggs LO206 @ #350




Idaho Unlimited All Stars:

Any 2 cycle engine up to 270cc or any 4 cycle engine up to 510cc.

Open Class Karts must meet all UAS Rule Book requirements.


There are a wide variety of engines that are used for the UAS Open Class.
Most common are Dirt Bike or ATV engines.
This class is for the more experienced racer!
UAS Open Class karts are the Super Modifieds of Speedway Karting!