With two weight divisions this class allows close competitive racing in karts with reliable engines (IAME KA100 Reedjet (fitted with a restrictor) or Yamaha KT100J) still fast enough to teach the basics of racecraft at a low cost. Eligible for Junior drivers in the year of 12th birthday to end of Year of 15th. Senior drivers are eligible but must hold a senior licence.
Approx. Power – 11hp
As from the 2016 Karting Australia Manual
KA4 Junior Chassis
Karting Australia states that the chassis must comply with all rules as described in the 2016 Karting Australia Handbook.There are no specific conditions that apply to this class. Popular in this class are chassis manufactured from 28mm tubing with rear axles that are either 30mm or 40mm. To cater for the taller Junior Driver the chassis wheelbase moves to a longer setup with generally 1010mm to 1030mm being available. There are many manufacturers of this kart class, you can choose from Arrow, Deadly, Monaco, FA, CRG, Tony Kart, Kosmic, Ricciardo and many more. We suggest you look for a brand that is commonly raced in the Griffith Kart Club, this will ensure availability of spare parts and advice from other experienced club members.
KA4 Engines[table id=8 /]
Most competitors in this class use the IAME KA100 engine with a restrictor fitted as this provides the best performance and reliability. The class can use the YAMAHA KT100J engine run without a restrictor but it is a good idea to consider the IAME KA100. On track performance has shown the IAME KA100 is a superior engine with noticeably better performance than the YAMAHA KT100J. The IAME KA100 is also used in next class up (KA3) and will provide you with the ability to progress without having to upgrade your engine. There is also a market for used IAME KA100 engines and should give better re-sale value than the older YAMAHA KT100J.
As per Karting Australia 2016 rules the following tyres are to be used in this class.For dry weather use Bridgestone DR10 YLR ROK, Front tyre size must be 4.5/10.0-5, Rear tyre size must be 11 x 7.10 – 5. Wet weather tyres are Bridgestone WER YLP Front Tyre size must be 4.5/10.0-5, rear tyre size must be 6.0/11.0-5.