34.11. Engine starter batteries and separate auxiliary data logger batteries where permitted must be fitted to a main Chassis Frame tube or within the confines of the main Chassis Frame and shall be placed on the Chassis Frame in an area located to the side of the seat opposite the engine and behind the central strut or alternatively mounted on or behind the seat. The battery carrier must be welded directly to the Chassis Frame or attached by means of tools to a minimum of two points on the Chassis Frame and in this case the following apply:
• Where attached to a chassis lug the bolt or bolts must be a minimum of M8 size.
• When utilising a clamp, all bolts must be a minimum of M6 size.
34.12. If Lithium batteries are used they must carry the appropriate“ EC” and markings.
34.13. All karts fitted with a self-starting system must also be fitted with an operational on / off ignition switch clearly marked with the relevant positions.
34.14. The Driver of a self-start kart must be in the seat when the engine is started if the Kart is placed on the ground or when it is running on the dummy grid. It is recommended that the brake is applied during the starting procedure.
34.15. Terminals and electrical connectors must be covered with insulating material.
34.16. No part of the cooling system is permitted to be located directly in front of the Driver’ s seat and may not pass over any part of the Driver’ s body.
34.17. All pressurised pipes must be reinforced and a catch tank is recommended on cooling systems with vented caps.
34.18. A retaining device is recommended on pressure caps. 34.19. The use of inhibiting agents including anti-freeze is permitted.
35. Transmission
35.1. The transmission is the method of transferring drive from the crankshaft drive sprocket to the back axle sprocket.
35.2. For some Classes this drive may have a variable ratio gearbox interposed between engine and back axle sprocket.
35.3. Direct drive Classes must not be fitted with a variable ratio transmission. However they may be fitted with a clutch if permitted in Class Regulations.
35.4. Clutches are recommended for all Bambino Cadet Inter and Junior Categories and are mandatory for all new Cadet and Junior ASN homologated engines.
35.5. Karts competing in the Gearbox Classes must be equipped with a variable ratio transmission providing a minimum of two speeds and must be fitted with a clutch.
35.6. All Classes must use axles of magnetic Steel material with a maximum external diameter of 50mm.
35.7. The axle wall thickness at all points( except in keyway housings) must comply as minimum to the dimensions shown in the table below. Exceptionally axles for use in 210 and Superkart 250 Mono Classes with a diameter greater than 40mm must have a minimum wall thickness of 2.9mm. Please also refer to Class Regulations for any variations.
Motorsport UK National Competition Rules 2026 Edition 1
Chapter 18 Appendix 8- General Technical Regulations 681