The bambino class is designed for 5-8year olds. The most popular engine is the Comer c-50 and tyres remain open for the 2019 season for this class. Cults Kart Club allows for proper racing with standing starts, and is proving to be a very popular class on race weekends. With speeds up to 40MPH, the class is a spectators favourite. Weights are set at 69Kg ( Kart and Driver ) and rear sprocket is set to 80t.


Boys and girls can start kart racing at the age of eight in Formula Cadet (Comer or WTP) or Honda Cadet, although some tracks will allow youngsters to practice from the age of seven. Then they can continue until the end of the year of their thirteenth birthday. The Formula Cadet uses a sealed 60cc 2-stroke engine, whilst Honda Cadet uses a un-sealed Honda GX160 4-stroke engine. They are allowed to race together. Both have a centrifugal clutch and recoil starter cord and modifications are limited to keep costs down. Chassis makes are registered and they must not be modified. Prices of new equipment are controlled to an agreed maximum. Maximum speed is about 55mph. There is a series for the MSA British Championship run for Formula Cadet within the BRDC Stars of Tomorrow series and an ABkC series in the Super One. Like all the direct drive classes there is a right hand foot pedal for the accelerator and a left hand foot pedal for the brake.

Formula TKM

Formula TKM can claim to be one of the U.K.’s most popular kart classes but only now in certain areas so do check at your local club. There are three classes, Junior TKM for age eleven to seventeen, and Senior TKM Extreme for those sixteen or over. As always, experienced Juniors can move into seniors in the year of their sixteenth birthday. To make racing equal and keep costs down, all the categories use a Tal-Ko TKM BT-82 piston port 100cc (115cc for Extreme) engine to a strict non-tuning regime, but the Junior categories have restrictors between the carburettor and engine to limit the power, with different sizes and class weights to suit the size of the driver. Maintenance costs are reasonably low. As in all racing kart classes, the minimum all-up class weights in each class vary to cater for the different age and driver sizes. (Lead ballast is used to bring the weight up to the minimum weight if necessary.) Additionally only chassis that have been registered for the class are permitted, and maximum retail prices are set each year. Optional clutches are permitted, in which case a portable external electric starter is needed. Without this direct drive karts need to be pushed to start, initially with the rear wheels off the ground until enough speed is reached to start the engine. TKM is recommended for those starting 2-stroke karting, so long as it is raced at your local club. Top speeds are about 65 to 70 mph. More information is on the Tal-Ko Website.

Rotax Max, DD2, Rotax Junior UK and MiniMax

The Rotax Max uses a racing pedigree 125cc 2-stroke direct drive engine with an onboard clutch and electric self starter. The engine is quite powerful, although the maximum revs are limited, making the karts almost as fast as ICA or Formula A. The engines are much lower maintenance than the 100cc alternatives, and are sealed so that only approved dealers can service them, making sure no unapproved tuning is carried out. Rotax Max is the senior class, with Rotax Junior UK the junior equivalent for 13 to 17 year olds. The junior engine uses a less powerful cylinder and MiniMax is an even more restricted version for 11 to 17 year olds. Becoming very popular but careful consideration as to racing experience is needed before choosing these classes to start in. Rotax offer an all expenses paid World Final for selected senior drivers qualifying from their home championships. These are now the most popular classes in the UK. There is a Rotax Max/177 class for the heavier drivers which is gaining in popularity. The Rotax family classes are the most popular karting classes in the UK. The Rotax DD2 class uses a similar 125cc two stroke engine, but has two gears changed with steering wheel mounted paddles. There is a championship class in the Super One Series, and they use a slightly more grippy tyre.


A CIK (European and world wide) class for 13 to 16 year olds (from age 12 if prior experience). The engines for the KF series are all derived from the base KF4 125cc TAG (Touch And Go – electric on board starter) two strokes from many manufacturers with different restrictions for the different classes. For instance KF3 is restricted to 14,000rpm and a specific carburettor type. Mainly raced at British Championship level within the Super 1 Series, with some clubs and the Stars of Tomorrow also catering for this class. It uses relatively grippy tyres and provides a route for Juniors to partake in world level karting. The chassis must be CIK homologated which means all the parameters have been registered for use in a particular class. Not really a class for beginners!


A medium to high cost class for seniors using a 125cc TAG engine, homologated with the CIK and with internationally homologated chassis types and quite grippy tyres. The engines can rev up to 15,000rpm maximum. This class is the principal stepping stone for seniors into the European CIK championships through regional qualifying events. The class is hotly contested at Super One championship level and it is not really a class to start in.


The premier direct drive class for seniors. It uses the KF 125cc engine with fairly open tuning but restricted to 16,000 rpm maximum, and very grippy tyres, especially at European and World level. Primarily raced for the MSA British Kart Championship within the Super One Series. Like KF2 and KF3, chassis from a manufacturer with CIK homologations must be used. It is not a class to start in. Top speeds can be over 80mph.

4-stroke Classes

As well as Honda Cadet there are two further budget 4-stroke classes. Honda Junior utilises two Honda GX120 or 160 engines and is aimed at eleven to seventeen year olds, whilst Honda Senior uses two Honda GX160 engines for seniors of sixteen or older. Like the other classes, juniors may move into seniors in the year of their sixteenth birthday. Only certain clubs run 4-stroke classes, e.g. the Formula 6 Association. The Honda senior prokart is also often used in endurance racing over several hours with teams of drivers sharing karts. As well as the budget 4-strokes there are several bespoke racing 4-stroke engines including a TKM for juniors and seniors with a healthy ABkC series in the Super One, and a Biland. The relatively new World Formula offers economical 4-stroke kart racing, and is modelled on the CIK’s world wide formula. Not all clubs offer 4-stroke racing though, whilst some specialise in this aspect of karting.

Gearbox Classes

For drivers over 16 years on short circuits. For long circuits like Donington or Cadwell Park drivers can start so long as they are no longer a novice, and are over 16 years old in the 125 and 210 classes, and over 17 for the 250 classes. ABkC national Super 4 short circuit championships are split between the BRDC Stars of Tomorrow and the Northern Karting Federation (NKF) series.

Junior Gearbox 80

This class uses an 85cc TM or Honda 2-stroke engine with 6 gears and a clutch and is for 13 to 16 year olds, all other gearbox classes being for seniors over 16. With its four wheel braking it offers juniors an experience close to a single seater race car or of course the senior gearbox categories. This class no longer has a national championship. Some clubs offer this class at selected meetings only.

Formula ICC UK / KZ2 UK

A medium cost class using registered 125cc water cooled reed valve 6-speed engines for seniors. This is a good entry point for the gearbox classes with good grids and plenty second hand equipment. The gearbox classes use either a hand clutch or a foot clutch just like a car. All use foot pedals for the throttle and brake. Tuning is restricted, and a lower compression ratio helps to give the engine a long life. The Dunlop SL4 tyres used in the 125cc classes are economical to buy and have a long life. ICC UK may be raced at its class weight within the Open class. There is a KZ1 / Super ICC category, mainly raced as the premier ABkC Super 4 championship within the BRDC Stars of Tomorrow. The only difference is the lighter class weight and grippier tyres.

Formula 125 Open

The fastest 125cc gearbox class using mainly CIK homologated (registered and approved) makes of reed or rotary valve 6-speed engines. The class is very similar to the international but now obsolete Formula C. A little more expensive than ICC, and speeds of 90mph (short circuit) and 115mph or more on the long circuit tracks are attained. This is primarily a club class at short circuit, but also has a similar long circuit championship. The weight for the class is 5kg heavier than KZ2 / ICC UK so that the two classes can race together fairly equally. For 2009, the non-CIK homologated karts will be permitted to run with no front fairing or bodywork, so long as they are fitted with double rail sidebars.

Formula 210

A classic class using only the Villiers 197cc engine or clones. Administered by the drivers themselves through the 210 Challenge group. Further details from Kate Bateman on tel: 01527 870834 or from The group promotes a very popular 210 Challenge which goes around the club meetings, mainly in the Midlands.

Formula 250 National

A popular class, especially on short circuits, using registered motocross 5-speed 250cc single cylinder 2-stroke engines. Like all the 250’s the karts are often equipped with large full width nose cones and rear wings. The powerful 250’s can reach speeds of 100mph on short circuits, and over 140 mph on long circuits. This class is also the MSA British Long Circuit championship. A similar class raced internationally is SuperKart Division 2, but a different range of engines are permitted. The NKF holds the ABkC Super 4 series for the national championship.

250 Superkart Division 2

A CIK international class. It uses a five or six speed mono cylinder registered engine, the most popular of which is the 5-speed Honda, the 6-speed Rotax 257 and from 2004 the Gas Gas. No longer raced at short circuit.

Formula 250E and Superkart Division 1

The fastest gearbox class with a powerful twin cylinder 250cc 2-stroke and six gears. Now two 125cc engines are allowed too, i.e. a twin engined kart. Capable of speeds up to 160mph at the fastest motor racing tracks. It is still raced for major championships as Superkart Division 1 in certain continental countries and has a CIK European Championship, but now is generally a non-professional class in the UK administered by a development group to limit further costs as 250E. No longer raced at short circuit tracks.