- Bore and Stroke: 66,4X72
- Displacement: 249
- Compression ratio: N.A.
- Horse power: N.A.
- Aspirazione: V-Force Reed valve
- Carburettor: Keihin PWM 38
- Fuel: Super-unleaded
- Ignition: Kokusan Electronic
- Clutch: Multiple-disk in oil bath with hydraulic control
- Gear: 5 gear / 6 gear option.
- Cooler System: Coolant liquid with pump
- Frame: Perimetral aluminium section
- Front fork: KYB 48mm
- Rear shock: TM Racing
- Front tyre: 100/90 X21
- Rear tyre: 110/90 X 19
- Front brake: Braking wave Disk 270 mm. With Brembo pump and Brembo caliper
- Rear brake: Braking wave Disk 245 mm. With Nissin pump and caliper
- Tank: Plastic 8,7 litres
250cc / 300cc: Single Cylinder, Water-Cooled, TMEES Powervalve.
Hand finished crankcases. Lightweight and strong die-cast clutch casing, clutch inspection, water pump and ignition covers. Aluminium water pump rotor. Billet machined crankshafts running on roller bearings with ‘hi-tech’ crank-seals. Friction reduction coated pistons. High performance – long lasting clutches. ‘Cush-drive’ clutch baskets. Friction reduction hard coated clutch baskets. Friction reduction hard coated gearbox selector fork tips. Hardened / treated gear-shaft parts. MX / EN gearboxes with differing ratios – 5 and 6 speed with options available on MX/SMX models. Hydraulic clutch actuation. V-Force reed blocks. Keihin carburettors (MX/SMX/FT). Emoticon controlled ‘TBi’ fuel Injection systems with separate electronic control oil distribution. Electric start. Balancer shaft. HGS Exhaust systems (with plated expansion chambers on EN / Road models). TMEES electronic exhaust valve control. Kokusan digital variable advance ignition with twin map selection. Gear position sensitive variable ignition timing / power-valve control and fuel injection system operation.
The large capacity TM Racing 250cc and 300cc 2-stroke engines are synonymous with strength and durability, with each capacity engine having its own unique qualities in the terms of performance and power delivery characteristics. In 2019 the engines had a total re-design which featured a multitude of new and exciting additions to increase performance and ease of use for the rider, these engines were then updated once again in 2020 for the release of the fuel-injected variants, these changes remain and are adopted across all models. For the new model year we only see some small changes and revisions to these already ‘complete’ engines, including new crankshaft tolerances, revised cylinder ports and a new balancer shaft bearing set-up. There are also updates specific to the ‘Fi’ variants which include alterations in the fuel injection control system for better performance.
Whilst retaining some internal components, from the exterior, the latest generation engines have a whole new look and share nothing in terms of cast components and little in internal components with the previous class engine that was phased out in 2017. The complete re-design of this latest engine was born and produced to accommodate numerous changes, changes that include electric start on all models, alongside a fuel injection option on ‘road’ models with a digitally controlled oil distribution system. The gearbox assembly also features friction reduction coated and treated parts to ensure smooth and precise shifting and a whole new gearbox assembly for the Enduro variants featuring 6 ratios (option on carburettor models). The recent addition of a balancer shaft reduces engine vibration, giving smoother performance, better ‘feel’ and a reduction in rider fatigue. The gear position sensitive ignition works alongside the TMEES exhaust valve control system, with the servo mounted to the cylinder and working directly to a revised pulley system. Electronic control programming, alongside the handlebar mounted twin ignition map switch, allows the power delivery for each of the 250cc and 300cc engines to not only be tailored by the rider on track, but the electronic systems also make alterations to the mapping depending on gear selection, valve position, rpm (and communication to the fuel injection system where applicable), always ensuring the best power delivery and traction. A system that is proving to be great for the hole-shot and those slippery rock sections alike, depending on machine and discipline of course, thus allowing the engine and control systems to give the rider the required power and torque at the required time to give the best in performance in all conditions. Constructed from some of the best materials for maintaining performance and reliability these already class leading engines that produce incredible, yet usable, controlled power and torque combined with quality ancillary components, have taken themselves to a new level. Power delivery, rider comfort and ultimate outright performance is optimally tailored in each discipline in all conditions in a way never seen before in off-road 2-stroke engines.
The high-end specification of all TM Racing machines is well-versed and this model year is no exception. The specification list for a ‘production machine’ is vast and features numerous high-quality components throughout. For 2023 we have several small changes and revisions to further enhance the ‘new for 2022’ chassis that was already designed to improve handling, weight balance, overall machine weight (reduced), rider ergonomics and the visual look. All variants chassis’ and sub-frames will once again be constructed using aluminium, with each engine ‘capacity’ / variant having a chassis unique to that engine displacement. This ‘tailoring’ of the chassis to engine allows TM Racing to design and build each machine for minimal weight, compactness, and better handling characteristics with mass centralisation specific to each model whether 2-stroke or 4-stroke. All chassis are constructed using the latest design elements that reduce overall chassis weight whilst maintaining maximum strength, matched to new revisions in chassis geometry / triple clamp angles that are specifically tailored to each model once again, allowing the best in handling characteristics for each model in the range. On all models, the now standard fitment KYB 48mm twin chamber fork, will continue to adopt the latest generation of internal friction reduction ‘coatings’ with some revised settings from 2022. These latest generation forks are designed to give improved response for faster changes to the terrain, all still controlled by the more favourable spring and oil set-up which is still proving to give greater reliability and more consistent performance. The TM Racing shock absorber, made in house by the TM racing technicians, has seen some large internal changes over the last 2 years and will still adopt this latest ‘seal’ system designed to reduce friction and increase shock performance. Combined with the latest swing-arms, linkage components and spindle diameters to limit and ‘control’ flex, the shock allows for a more progressive feel, giving improved track stability and maximising traction. The chassis and suspension components work together to achieve incredible handling characteristics on a multitude of surfaces, allowing for greater stability in all conditions, increasing traction and inspiring greater confidence to reduce lap-times. The aesthetic look of the machines will remain as per 2022, where the latest chassis generation is not only ‘form’ but ‘function’, reducing the width of the bike reduced by 3cm to create a slimmer machine with better rider ergonomics and more freedom of movement. The current appearance of the latest generation model range is still one of the most striking to date, a mix of angles and curves that blend seamlessly into each other from front to rear. Beautiful, yet aggressive in its shaping, the body panels will feature a new decal scheme for 2023 incorporating some brighter colour accents giving a more striking visual appearance.
‘FRESH AIR SYSTEM’: All TM Racing adult 2-Stroke models feature the ‘Fresh Air’ intake system which allows the engine air filtration system to breathe cleaner air, this system reduces particulate contamination of the air filter maximising power for longer duration. Air is channeled from the intake vents – via the radiator panels and fuel tank – to the airbox which houses a large volume air filter. The ‘Fresh-Air’ system also brings another added advantage in the form of a lower centre of gravity, with the fuel tank now positioned slightly further into the chassis around the engines cylinder, this ‘weight’ shift, combined with the latest frame geometry and suspension, all work harmoniously to maximise the handling characteristics of each machine. The 4-Stroke machines also continue with ‘reverse’ layout, which sees the fuel tank moved under the seat area whilst the engine intake and filtration system is now positioned above the engine. This allows the 4-Stroke engine to breathe cleaner air with a much more direct air feed into the Fi throttle body, filter contamination is decreased whilst engine performance and response is maximised. This chassis layout witnessed a huge transformation to the complete range of 4-stroke model machines, with the centre of gravity lowered further into the chassis, especially when noting that each capacity model has its own main chassis unique to a specific engine base. TM Racing have created a line of incredibly nimble and agile machines, better handling characteristics, turning, stability and weight losses were seen throughout the current chassis guise as well as gains in engine performance.
WHEELS: The CNC machined billet aluminium hubs, laced to anodized Excel rims, feature the latest spoke arrangement with a ‘tapering’ design profile in a stronger material, a material treated to increase corrosion resistance, larger spoke nipples feature on the front wheel also for added strength. The wheel configuration allows for the best in strength and durability of the wheel components whilst reducing the un-sprung weight by a small margin. The CNC machined hubs, featuring external dust seals encircling CNC machined wheels spacers to further protect the wheel bearings, are mounted to the suspension components via large diameter hollow spindles. The larger diameter spindles, machined through their centres to lower weight, allow for a more rigid fixing off the wheel reducing the flex and allowing the suspension to work more effectively.
BRAKING SYSTEMS: The braking systems for the TM racing model range has also received some new components in the form of some new options for the SMK range and new Brembo front brake pumps for some adult models. The entire model range continues to feature high quality oversize wave discs working with TM Racing’s ‘mix’ of components. The master cylinders are connected to the brake calipers with lined and braided high quality racing brake lines that are designed to minimise expansion and ensure maximum braking effort is always transmitted to the calipers. This tried and tested collaboration of parts is regarded as one of the best braking systems in many tests and by racers alike. These braking systems keeps performing in the harshest conditions giving great efficiency and inspiring confidence always. The rear brake system is actuated by a twin bearing pivot-mounted, billet machined aluminium foot lever with a replaceable tip.
TRIPLE CLAMPS: The triple clamps fitted to TM Racing motorcycles competition range are CNC machined from block aluminium and each clamp is a work of art. The clamps intricate machining, most of which can only be seen from the underside, gives a structure designed to be supremely strong whilst keeping weight to minimum. The triple clamps also come with an optional ‘damped’ bar mounting system that through a tapering rubber cone arrangement, allow vibrations that can be transmitted through to the handlebar area to be reduced, whilst also allowing some ‘give’ to the bars in the event of a fall reducing the chances of more severe damage occurring to the handlebars and the components adorning them. The handlebars are secured, via the optional ‘damped’ bar mounting system, by billet machined bar clamps, with the top bar clamps featuring a machined TM Racing logo on their upper face.
CLUTCH ACTUATION: All TM Racing machines come fitted with a Hydraulic actuated clutch as standard, the master cylinder, made by Brembo, transmits fluid via a lined and braided hydraulic line to TM Racing’s own ‘slave’ cylinders. With separate slave cylinders for the 85/125/144 engines, the 250/300 engine, the 250Fi/300Fi engines and the 450Fi and 530Fi engines, each unit designed to fit and perform for each model giving a balanced clutch feel between all engine size variants, with both single and dual seal pistons in the slave cylinders depending on model application. The Brembo master cylinders, working with the braided hose that limits hose expansion under extreme load, gives great feel and precise clutch control with great durability when combined with TM Racings ‘cush-drive’ (hard coated) clutch baskets, which on all variants 250cc and over, are coated with a hard wearing, friction reduction coating. All clutches are multiple disc ‘wet’ units with multi sprung pressure plates.
ELECTRIC STARTING: The ES abbreviation in any motorcycles descriptive from the TM racing range denotes that the machine has ‘Electric Start’. The TM Racing Electric start system is powered by a new, lightweight, Lithium-Ion battery that is recharged during engine running by the electrical system. Electric start is now standard fitment on all models and engine capacities over 144cc.