Class guide, 2026
Kart classes
The 17 classes in the Motorsport UK Karting Yearbook 2026, grouped by age category, with the series that race each one.
Non-gearbox · ages 6-8
Bambino
The first step in kart racing, for drivers aged 6 to 8.
- 12
MightE Bambino
Motorsport UK homologated electric powertrain.
- Ages
- 6-8
- Min weight
- 83 kg · driver 21.5 kg
- Plates
- Blue/White
- Tyres
- Le Cont MSA04 dry, Le Cont MSA04 wet
MightEYearbook p.11
Also recognised: Comer Bambino. Regulations for these are published separately by Motorsport UK or the class owner, and clubs need Motorsport UK approval to run them.
Non-gearbox · ages 8-12
Cadet
For drivers from 8 to 12, moving up from Bambino.
- 12
MightE Cadet
MightE Gen 4 electric Cadet powertrain.
- Ages
- 8-12^
- Min weight
- 118 kg · driver 31 kg
- Plates
- Blue/White
- Tyres
- Vega Cadetti 'UK' dry, Vega WM1 CIK wet
Motorsport UKYearbook p.18
- 12
IAME Water Swift (restricted)
Restricted version of the Water Swift Inter engine. Removing the exhaust restrictor turns it into the Inter engine.
- Ages
- 8-12^
- Min weight
- 100 kg · driver 26 kg
- Plates
- Yellow/Black
- Tyres
- Vega Cadetti 'UK' dry, Vega WM1 CIK wet
Argenti-KTYearbook p.19
- 12
Honda Cadet
Honda GX200 4-stroke engine with clutch.
- Ages
- 8-12^
- Min weight
- 105 kg · driver 28 kg
- Plates
- Yellow/Red
- Tyres
- Vega Cadetti 'UK' dry, Vega WM1 CIK wet
Anderson-CSK MotorsportYearbook p.23
- 12
Rotax Micro Cadet
Restricted version of the Rotax 125 Junior MAX engine.
- Ages
- 8-11^
- Min weight
- 105 kg · driver 28 kg
- Plates
- Yellow/Black
- Tyres
- Vega Cadetti 'UK' dry, Vega WM1 CIK wet
Raced in
JAG (UK)Yearbook p.24
- 12
Rotax E10 Cadet
Rotax E10 electric Cadet powertrain.
- Ages
- 8-12^
- Min weight
- TBC kg
- Plates
- Yellow/Black
- Tyres
- Vega Cadetti 'UK' dry, Vega WM1 CIK wet
Raced in
JAG (UK)Yearbook p.28
Also recognised: IAME Gazelle, Honda GX160 Cadet, Tillotson Cadet. Regulations for these are published separately by Motorsport UK or the class owner, and clubs need Motorsport UK approval to run them.
Non-gearbox · ages 10-13
Inter
A step between Cadet and Junior, for drivers from 10 to 13.
- 12
IAME Water Swift
Unrestricted 60cc water-cooled engine.
- Ages
- 10-13#
- Min weight
- 110 kg · driver 31 kg
- Plates
- Yellow/Black
- Tyres
- Komet K1D-M dry, Komet K1D-W wet
Raced in
Argenti-KTYearbook p.33
- 12
Rotax Inter
Restricted version of the Rotax 125 Junior MAX engine.
- Ages
- 10-13#
- Min weight
- 115 kg · driver 33 kg
- Plates
- Yellow/Black
- Tyres
- Mojo C2 CIK dry, Mojo CW CIK wet
JAG (UK)Yearbook p.36
Also recognised: Tillotson Inter. Regulations for these are published separately by Motorsport UK or the class owner, and clubs need Motorsport UK approval to run them.
Non-gearbox · ages 12-16
Junior
Full-size karts with restricted 125cc engines, for drivers from 12 to 16.
- 12
IAME X30 Junior
As IAME X30 Senior but with an exhaust restrictor.
- Ages
- 12-16*
- Min weight
- 148 kg · driver 41 kg
- Plates
- Yellow/Black
- Tyres
- Komet K3H dry, Komet K1W / K3W wet
Raced in
Argenti-KTYearbook p.41
- 12
Rotax Junior Max
Junior version of the Rotax 125 Senior MAX engine.
- Ages
- 12-16*
- Min weight
- 145 kg · driver 40 kg
- Plates
- Red/White
- Tyres
- Mojo D2XX 'CIK' dry, Mojo W5 'CIK' wet
Raced in
JAG (UK)Yearbook p.45
- 12
Tillotson T4 Junior
4-stroke Junior version of the Tillotson T4 engine. Single-chassis class: everyone races the same Tillotson chassis.
- Ages
- 12-16*
- Min weight
- 143 kg · driver 40 kg
- Plates
- Yellow/Black
- Tyres
- Maxxis T4 dry, Maxxis T4 Wet wet
TillotsonYearbook p.49
Also recognised: Formula Libre Junior. Regulations for these are published separately by Motorsport UK or the class owner, and clubs need Motorsport UK approval to run them.
Non-gearbox · ages 15+
Senior
The main non-gearbox classes for drivers from 15 upwards.
- 12
IAME X30 Senior
125cc water-cooled TAG engine with electric start.
- Ages
- 15+**
- Min weight
- 162 kg · driver 53 (under 16) kg
- Plates
- Yellow/Black
- Tyres
- Komet K3M dry, Komet K1W / K3W wet
Argenti-KTYearbook p.52
- 12
Rotax Senior Max
125cc water-cooled TAG engine with electric start.
- Ages
- 15+**
- Min weight
- 162 (under 16: driver 52) and 177 (driver 83) kg
- Plates
- Blue/White
- Tyres
- Mojo D5 'CIK' dry, Mojo W5 'CIK' wet
Raced in
JAG (UK)Yearbook p.56
- 12
TKM Extreme
BT82 115cc piston-port engine, optional clutch, optional TAG. Weight and restrictor bands let drivers of different sizes race together.
- Ages
- 15+**
- Min weight
- 132+ kg · driver 40+ (under 16) kg
- Plates
- Red/White
- Tyres
- TKM Maxxis Sport dry, Maxxis Red/White 'TKM' wet
Raced in
Tal-KoYearbook p.60
- 12
Tillotson T4 Senior
4-stroke Senior version of the Tillotson T4 engine. Single-chassis class.
- Ages
- 15+**
- Min weight
- 161 kg · driver 52 (under 16) kg
- Plates
- Yellow/Black
- Tyres
- Maxxis T4 dry, Maxxis T4 Wet wet
TillotsonYearbook p.72
Also recognised: Formula Libre, Tillotson Senior. Regulations for these are published separately by Motorsport UK or the class owner, and clubs need Motorsport UK approval to run them.
Gearbox · ages 13-17 (Junior), 15+ (Senior)
Gearbox
Karts with gearboxes, from Junior Gearbox up to KZ2 and 250cc Superkarts.
- 12
KZ2
125cc international gearbox class, following the CIK-FIA KZ2 rules with a few UK differences.
- Ages
- 15+a
- Min weight
- 180 kg
- Plates
- Yellow/Black
- Tyres
- Le Cont LPM 'CIK' dry, Le Cont LWR 'CIK' wet
Raced in
Motorsport UKYearbook p.74
- 12
Superkart 250
Registered gearbox engines up to 250cc.
- Ages
- 16+
- Min weight
- 195 / 200 / 208 kg
- Plates
- White/Black
- Tyres
- CIK-FIA homologated dry, CIK-FIA homologated wet
Motorsport UKYearbook p.76
Also recognised: Junior Gearbox, 125 Open, 210 National, 450 4-stroke. Regulations for these are published separately by Motorsport UK or the class owner, and clubs need Motorsport UK approval to run them.
Age key
- ^
- From the calendar year of the 8th birthday, with the required Bambino experience.
- #
- From the calendar year of the 10th birthday, with a Kart National licence.
- *
- From the calendar year of the 13th birthday, or from the 12th birthday with a Kart National licence.
- **
- From the calendar year of the 16th birthday, or from the 15th birthday with a Kart National licence, or any International ITE licence holder.
- a
- From the calendar year of the 16th birthday with a Kart National licence and at least 10 kart events at 3 or more venues, or from the 15th birthday with an International ITE licence.
Source
Motorsport UK Karting Yearbook 2026, Version 1.1, Introduction note 5 (Categories and Classes) and Appendix 9 (Kart Classes at a glance). Weights are the minimum for kart and driver in race condition. Class regulations change; always check the current Yearbook, the Motorsport UK resource centre and the meeting's supplementary regulations before you race.