The main regulations for all motorsport in the UK is found in the Motorsport UK Yearbook, including the Kart Section U.  There are important sections for licencing, judicial and safety which apply to kart racing.  Click here for the whole 2022 book

Also check back for updates on the Motorsport UK website, go to Resources and tick the Yearbook section then search, as they are ‘live’ documents.

The regulations for the core classes are found in the Karting UK Yearbook. Click here for a copy of the 2022 Karting Yearbook (known as the Gold Book)

Honda Tech Regs V17 Approved for 2022 and an Introduction to the changes for 2021

Note this clarification / explanation issued on 27.6.19 (kept here to assist newcomers):

An updated, more environmentally-compliant Honda T2 engine is now in circulation with engine preparers and will be seen at circuits. The external method of identifying this engine is that the engine number will start with a “4”. The only other obvious identifying factor is that the flywheel magnet might well be mounted in a green coloured holder. 

2016 Honda Technical Regulations V11a  this version is needed for those with T1 engines.

Smaller or new classes, or variations to the major classes, will have their own set of regulations, usually by way of a KTE (Kart Technical Exemption).

Here are some of the popular KTE’s, some of which have not been renewed recently

Junior Gearbox (2021 draft version V2 now)

210 National (2021 Version, updated 1.9.21) 2022 coming soon

450 4-stroke Gearbox (2019 version)

Gillard Junior Tyro (2018 awaited)

Clubs can also offer the Clubman classes (which are lower powered and do not need the driver to take the ARKS Test so  Clubman licence is required and can be taken out on the day of the race if necessary) or Libre classes (which do need the ARKS Test).  Between them they cater for engines which are no longer homologated with their own class structure, or clubs wishing to combine a class with several compatible engines or use an engine that may not be in the regular homologated class approvals. Motorsport UK is open to new approvals for Clubman or Libre.

Formula Clubman, and approved variations for Honda Senior, World Formula and Junior Clubman with one Honda engine

Formula Libre, and the approved variation for

Junior Libre with two Honda engines

All of the above regulations can be found on the Motorsport UK Website

The best way to find up to date kart regulations is to visit the Motorsport UK Resource Centre page, and tick “Technical – Kart” for a search

Some other past information which may be of use:

Guidance Sheet for the new bumper regulations 

International Regulations and lists of homologated equipment, including racewear, can be found on the CIK Website

Homologations are a method of certifying certain equipment, and are usually valid for a certain number of years, with regular dates (often every three years) for new applications.  This method means that the sport has stability as equipment cannot be updated at a whim by the suppliers.  The fiche is the technical document describing the equipment in often great detail.  Competitors should have copies of the homologations and fiche for the equipment they are using.

Club regulations (supplementary regulations or championships regulations) must be approved by Motorsport UK and must reference which classes are being offered and where the regulations for these classes can be found.  Clubs usually put their local regulations on their website, see club listing.  The championship regulations will also show how points and penalties are calculated.


Summary of Main Kart Classes for 2022 – see the 2022 Gold Book last page for the class table

Number Plate/No. Weight kg (with driver)


Ages Tyres – Dry Tyres – Wet Comments
Bambino White/Black 69 or 71 if racing 6-8 Le Cont MSA04 Le Cont MSA04 Comer C50 MSA homologated 2-stroke engine
IAME Cadet Yellow/Black 103 8-12 Dunlop SL3 MSUK KT3 Barcoded 60cc Parilla Gazelle un-sealed engine, clutch, pull starter
Honda Cadet Yellow/Red 103 8-12 Dunlop SL3 MSUK KT3 Barcoded GX160 4-stroke budget engine, clutch, pull starter
Junior TKM 2S Blue/White From 123 11#-16 Maxxis TKM Green F TKM As TKM with restrictor, optional clutch, optional TAG
MiniMax Yellow/Black 132 11-14 Mojo D2XX CIK Mojo W5 CIK Restricted version of Rotax Junior Max
Junior Max Red/White 148 13-16 Mojo D2XX CIK Mojo W5 CIK Junior version of Rotax Senior Max
MiniX White/Black 132 11-14 Komet K2H Komet K1W Restricted version of X30 Junior
X30 Junior Green/White 148 13-16 Komet K2H Komet K1W Junior version of X30 with restrictor
OK Junior Yellow/Black 142 12-16 TBA TBA Junior version of OK, these are push start karts, not currently raced in UK
TKM 2S Extreme Red/White From 132 16# Maxxis TKM Green F TKM 115cc BT82, optional clutch, optional TAG
Rotax Max Blue/White 162 16# Mojo D5 CIK Mojo W5 CIK 125cc d/drive commercial TAG class (electric start)
Rotax Max/177 Green/White 177 16# Mojo D5 CIK Mojo W5 CIK Heavy-w’t version with 83kg min driver weight
X30 Senior Yellow/Black 162 16# Komet K2M Komet K1W Commercial TAG 125cc IAME engine, not sealed
OK Senior Yellow/Black 152 16 TBA /TBA TBA / TBA International, not raced in UK
Formula Libre & Clubman Various   16# Various Various Catering for economy or minority classes such as Honda Junior and Senior, World Formula and older engines
KZ2 Yellow/Black 180 16 Le Cont SVC CIK Le Cont SV1 CIK International & British Championship 125cc gearbox class
250 National White/Black 195/200* 16+ Dunlop,Vega all CIKOption Same makes as Dry Motocross 250cc single cylinder engines, 450 4-stroke and 175 IAME 2-stroke options, 125 Open may race in this class



Key: + means 17 years minimum for long circuit racing. 2S: 2-stroke engine; 4S: 4-stroke engine (Classes are 2S unless otherwise shown)

# means year of the birthday with a National licence.

Many class regulations call for specific tyre markings on the tyres e.g. ABKC, JAG, MSA, MS UK, GB etc, See Kart Race Yearbook.

Junior classes have a minimum driver weight, for safety reasons. Junior TKM 37kg & MiniX, MiniMax 37, Junior Max, 42.5, and seniors for under 16’s.

Junior Max & Junior X30 may race in year of 13th birthday for experienced drivers

*250/210 Gearbox has two weights, one when short circuit or no bodywork is fitted, the heavier for when wings or long circuit bodywork is fitted.

Here are a couple of handy images demonstrating the class age ranges and possible driver weight range: