Rotax Plasma Cylinder 2027: What Changes, Who Needs It and Recommended Jetting
Updated: 3 days ago
For 2027 the Rotax MAX family gets a new heart: the Rotax Plasma cylinder, made directly by BRP-Rotax in Austria, together with a new Rotax piston. It becomes mandatory on Micro and Mini and is optional on Junior and Senior. Here is everything you need to know before ordering it: what really changes, how to recognise it, what you need to fit it and how to set the jetting.
In short The Rotax Plasma cylinder has a bore finished with a plasma coating: it lasts longer but has the same power as the current cylinder. Under the Rotax global technical regulations it is mandatory on Micro MAX and Mini MAX from 1 January 2027 and optional on Junior MAX and Senior MAX. On Micro, Mini and Junior it is a 1:1 swap, on the Senior 3 parts are needed for the exhaust valve. It comes only in classes A and AB, and the DD2 version arrives in 2028.
What the Rotax Plasma cylinder is
The Rotax Plasma cylinder is the new cylinder for the Rotax 125 MAX evo engine family. BRP-Rotax has moved cylinder production and piston supply to its own plant in Austria, to secure a stable supply and maximum parity between engines, which is the core principle of the Rotax MAX Challenge.
• Plasma coating: the bore surface is finished with an advanced plasma coating process.
• Longer life: higher hardness and better lubrication extend the life of both cylinder and piston.
• Same power: performance and lap times are the same as with the current cylinder. It is not a faster cylinder: it lasts longer and leaves the factory always the same.
• New lettering: the casting only says ROTAX, without RACING, to avoid casting defects caused by the extra letters.
The new Rotax piston
Piston supply has also been moved by Rotax to its plant in Austria. The design stays the same, but production tolerances are much tighter and dimensional accuracy is higher: here too the gain is durability.
The new piston and its ring are compatible with the Plasma cylinder and with all previous cylinders, and the current Rotax piston with ring can also be fitted to the Plasma cylinder. Piston and ring can be used in any combination.
Rotax Plasma cylinder: who must fit it in 2027
• Micro MAX and Mini MAX: mandatory from 1 January 2027 under the Rotax global technical regulations.
• Junior MAX and Senior MAX: optional in 2027: the current cylinder and piston remain legal.
• DD2: for now only the piston changes; the DD2 Plasma cylinder is planned for the 2028 season.
Rotax points out that individual championships may differ from the global regulations, because of their season start date and the way the parts are introduced. Always check the 2027 technical regulations of your championship, or message us and we will tell you what your engine needs.
How to recognise it: Data Matrix code and A and AB classes
Every Rotax Plasma cylinder has a label with a Data Matrix code and the class letter. The Data Matrix returns a unique random number that Rotax uses for production quality traceability: it is not a serial number.
The letters A and AB indicate the bore tolerance class, used to pair the right piston during assembly. They are not quality levels. Thanks to the tighter tolerances class B has been dropped: the Plasma cylinder only comes in class A and class AB. In the Rotax repair manual class A is a bore from 54.000 to 54.010 mm and class AB from 54.010 to 54.015 mm.
Fitting: what you need on Micro, Mini, Junior and Senior
• Micro, Mini and Junior: the Plasma cylinder replaces the current one 1:1, without changing other parts.
• Senior: the exhaust valve flange has a new design and three extra parts are needed: gasket 450415, support plate 251337 and gasket 250230.
In the Rotax diagram: 1 gasket 450415, 2 support plate 251337, 3 gasket 250230, between the Plasma cylinder and the Senior exhaust valve.
• Piston and ring: old and new can be combined freely.
The cylinder is inside the engine seal: to replace it the engine must be opened and resealed by an authorised service centre, which updates the engine identity card. All the rules are in our guide to the Rotax engine seal.
Recommended jetting with the Rotax Plasma cylinder
With the new Plasma cylinder and piston pairing, Rotax gives these starting values: standard main jet with its range, air screw turns and optimum operating temperature.
Category | Main jet / normal range | Float height / drop (mm) | Air screw (turns) | Optimal operating temp (°C) |
Micro | 108 / 105-112 | 2.5 / 13 | 1.75 | 85-92 |
Mini | 115 / 112-118 | 3.0 / 14 | 1.75 | 55-60 |
Junior | 125 / 122-128 | 3.0 / 15 | 1.75 | 50-55 |
Senior | 126 / 124-128 | 3.0 / 15 | 1.75 | 50-55 |
These are starting values: the right jet depends on temperature, pressure and altitude, as we explain in our guide to Rotax jetting in hot, cold and wet weather. To have every size at hand there is the Dell'Orto main jet kit. For the DD2, Rotax will publish the values before the Plasma cylinder arrives.
Another 2027 change to check: connecting rods
The Rotax MAX Challenge 2026 global technical regulations already state that from 1 January 2027 connecting rods numbered 213, 365 and 367 will no longer be legal. If you are rebuilding your engine for the new season, check the number stamped on the rod and replace it together with the cylinder if needed.
Price and availability of the Rotax Plasma cylinder
According to Rotax, the Plasma cylinder and the new Rotax piston are available from October and the retail price has not increased compared with the current parts. At TKS RaceLab the Rotax Plasma cylinder has a launch price of €350 including VAT, reserved for the first 100 pieces available from the importer: after that it will cost the same as the current cylinder. The new Rotax piston with ring costs the same as the current piston. Message us on WhatsApp to order them or to put together your 2027 engine package.
Frequently asked questions
Is the Rotax Plasma cylinder mandatory in 2027?
Under the Rotax global technical regulations it is mandatory on Micro MAX and Mini MAX from 1 January 2027 and optional on Junior MAX and Senior MAX. Individual championships may have different timing: always check your own regulations.
Is the Rotax Plasma cylinder faster than the current one?
No. Rotax states that power and lap times are the same as with the current cylinder. What changes is the durability of cylinder and piston and the consistency of production.
Can I fit the Plasma cylinder without changing other parts?
Yes on Micro, Mini and Junior, where it is a 1:1 swap. On the Senior three parts are needed for the new exhaust valve flange: gasket 450415, support plate 251337 and gasket 250230.
What do A and AB mean on the Plasma cylinder?
They are bore tolerance classes, used to pair the right piston during assembly. They are not quality levels. Class B has been dropped.
Is there a Plasma cylinder for the Rotax DD2?
Not yet. On the DD2 only the new Rotax piston changes for now; the DD2 Plasma cylinder is planned for the 2028 season.
What jetting do I need with the Rotax Plasma cylinder?
Rotax recommends as a starting point main jet 108 on Micro, 115 on Mini, 125 on Junior and 126 on Senior, with the air screw at 1.75 turns. The jet is then adapted to temperature, pressure and altitude.
When is the Rotax Plasma cylinder available?
Rotax states that Plasma cylinders, new pistons and genuine spare parts are available on the market from October. You can order them from a Rotax service centre or a Rotax dealer such as TKS RaceLab.
Does the Rotax Plasma cylinder cost more than the current one?
No. Rotax states that the retail price of the Plasma cylinder and of the new piston has not increased. At TKS RaceLab the Rotax Plasma cylinder has a launch price of €350 including VAT for the first 100 pieces available from the importer; after that it will cost the same as the current cylinder.
Why did Rotax introduce the Plasma cylinder?
By bringing cylinder production and piston supply into its own plant, BRP-Rotax maintains performance parity between engines and ensures quality and continuity of supply.
Is the Data Matrix code on the Plasma cylinder a serial number?
No. The Data Matrix code returns a unique random number that Rotax uses to trace the production quality of the cylinder.
Why does the Plasma cylinder say ROTAX and not ROTAX RACING?
Rotax changed the logo on the casting and kept only the word ROTAX to avoid casting defects caused by the extra letters of the word RACING.
Source: Rotax Tech Tip 07 "Rotax Plasma Cylinder" (official Rotax PDF), Rotax MAX Challenge 2026 global technical regulations and Rotax 125 MAX evo repair manual (2024 edition).
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Read also: Rotax jetting in hot, cold and wet weather → · Rotax engine seal and technical regulations → · Dell'Orto VHSB 34 XS: complete setup → · Rotax conversion kit from Junior to Senior →
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Author: Sergio, TKS RaceLab | Published: 20 October 2026
TKS RaceLab is the Italian online store dedicated to karting: spare parts, accessories and everything you need to get on track. With Arrive & Drive you arrive at South Garda Karting (Lonato), Franciacorta, Cremona or Ala and find your kart ready to go. No hassle, just driving.
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