Dirt Classes

Junior Classes

Age: 7 to 8 year olds and new junior drivers
Engine:Yamaha KT100J with 13mm
Approx Power: 5.5 HP
Weight Class: no weight restrictions

Age: 8 up to 14 year olds
Engine:Yamaha KT100J
Approx Power: 10-12 HP
Weight Class: 100kg inc kart

The Yamaha KT100J is the only engine used in Junior?s under AIDKA racing. As with AKA- bitumen racing, engine modifications are very limited. Allowable modifications include Blueprinting which is the re-machining the engine to reduce friction and to allow the engine to be set up for maximum performance. Area?s such as compression, port durations etc all have certain specifications which must be met.

Junior karts generally have a shorter wheelbase, between 95cm to 101cm. The smaller kart is easier for younger drivers to steer and manuver. A junior driver may however decide to use a senior chassis if they feel it suits their needs better.

Senior Classes

KT Open
Engine: Yamaha KT100S
Aprox Power: 16-20 HP
Weight Class: Light-120kg Medium-140kg Heavy-160kg (including kart)

J Open
Engine: Yamaha KT100J
Aprox Power: 10-12 HP
Weight Class: 115kg (including kart)

100cc Open
Engine: 100cc reed or rotary, air or watercooled
Aprox Power: 30-35 HP
Weight: 140kg (including kart)

125 Open
Engine: Parilla 125cc Leopard or Rotax 125 Max,watercooled engine with clutch and electric start
Aprox Power: 26-28HP
Weight Class: Light 135kg Heavy 160kg (including kart)

Twin KT
Engine: Two Yamaha KT100S
Aprox Power: 36-40 HP combined
Weight Class: 160kg (including kart)

200cc Open
Engine: Two 100cc reed or rotary, air or watercooled
Aprox Power: 60-70 HP
Weight: 160kg (including kart)

The most popular of the senior classes is the KT open class, due to the number of competitors and the cost to compete in this class. Yamaha have been manufacturing the same engine (with some minor modifications) for over 20 years. This means that a 15 year old engine will still produce as much HP as a brand new engine. AIDKA allow this engine to be modified more than AKA. The KT100S Engine may be ported, there are no compression ratio restrictions and aftermarket parts may be fitted internally (except crank and ignition) The other class that is becoming more popular is the 125cc class. This class uses either the Leopard 125 engine or the Rotax 125 Max engine. They allow limited modifications under the rules and generally run with all genuine components supplied with the engine. The advantages of this class is that they are watercooled and have an electric starter motor so that you do not need to push start the kart.

Senior karts have a wheelbase between 102.5cm and 105cm wheelbase depending on the brand. There are different chassis available for different classes. Please ask for further information on this subject.