Ahead of the 2026–2028 FIA Karting homologation cycle, the Italian manufacturer has renewed its range of engines for both international and national classes, from MINI to Shifter, including the OK categories.
TM Kart presents its engines for the 2026–2028 period: KZ-R3, MINI 4/4B, OK S3-Senior, OK S3-Junior and OK S3-OKN. Building on a line-up already renowned for performance and reliability, TM Kart has introduced new engineering solutions to raise the standard of its power units even further. All engines are designed and manufactured entirely in-house and are intended for the global market. The vast amount of data collected on track, both from factory racing activities and through TM Kart’s worldwide dealer network, combined with the expertise of its design department, fuels a continuous process of research and development. Thanks to the contribution of specialised technicians, CAD-based design, extensive bench testing and precision machining on state-of-the-art five-axis equipment, TM Kart continues to refine its engines without altering the proven foundations of products that have been leading contenders in national and international karting competitions for many years.
The new KZ-R3, also offered in the Total Black version, reflects TM Kart’s philosophy for the engines developed for the 2026–2028 CIK-FIA homologation cycle. Innovation and continuity define this engine, designed for the KZ, KZ2 and KZ2 Masters classes, the Shifter categories regulated by FIA Karting. The product evolves from its predecessor: the KZ-R2, which achieved impressive results in just three years, including two world titles, seven European championships, three World Cups and three International Masters’ Super Cups. While refining all the features that made the previous model so competitive, TM Kart’s engineers have introduced a number of updates to increase its potential even further. Chief among them is a new clutch assembly, designed to transmit higher torque with a more compact layout than before, improving both performance and reliability. Efficiency has also been enhanced with a redesigned primary gear ratio, the result of detailed development work that optimised the tooth profile and established new gear values.
TM Kart has also introduced important updates for the new MINI 4/4B, the engine used in the 60 cc MINI class under FIA Karting regulations. As the successor to the MINI 3/3B, which claimed several victories in WSK competitions, the new unit features a redesigned head and cylinder with optimised cooling fins that improve heat dissipation. The development stems from extensive CFD thermal analysis, which also led to the design of new plastic shrouds shaped to maximise airflow around the hottest areas of the engine. Further refinements include a new intake duct, developed to enhance overall performance, and upgraded crankshaft seals that reduce power losses caused by friction.
The continuity pursued by TM Kart in the engines developed for the 2026–2028 CIK-FIA homologation cycle is most clearly reflected in its Direct Drive range for the Junior and Senior classes: OK S3-Senior, OK S3-Junior and OK S3-OKN. Both the engines used in the international FIA Karting OK and OKJ categories and the ones used in the national OK-N and OK-N Junior classes, also under FIA Karting regulations, have all been confirmed. Their core specifications remain unchanged, and TM Kart has therefore extended the homologation of each model. At the same time, the company’s engineers have thoroughly analysed on-track data to refine every performance detail. World Champion in 2023 and European Champion in 2024, the OK S3-Junior is renowned for its smooth, progressive power delivery. Together with the OK S3-Senior, a two-time European Champion, it features the latest developments in mechanical design, fluid dynamics and thermal stability. The OK S3-OKN, developed and refined following the same engineering principles, has also proved its competitiveness, winning the World Cup in OK-N Junior and finishing second in OK-N.
The pursuit of performance, reliability and ease of maintenance is the guiding principle behind every engine designed and built by TM Kart, as the company prepares to reaffirm the competitiveness of its entire line-up for the 2026–2028 CIK-FIA homologation cycle.