Why are rotax engines sealed?

Why are Rotax engines sealed by Service Centres world-wide?

To participate in any officially sanctioned Rotax Max Challenge series world-wide you need to have your engines sealed by an accredited Rotax Service Centre.

Is this just a money-making racket or does it really add value?

Motorsport South Africa (who previously governed the South African Rotax Max Challenge) has stated in its 2021 karting regulations that Rotax competitors do not need their engine sealed in the MSA series – clearly this only applies to the ROK/KZ/OKJ/MSA karting events. The South African Rotax Max Challenge (run under KSA WOMZA) is the only BRP Rotax sanctioned series and the only way to qualify for the Rotax World Finals. The Rotax engine sealing system is a key part of the Global Technical regulations so any class or event running without the Rotax seals is not a “Rotax class” and cannot be referred to as a “Rotax Junior Max” or a “Rotax national” for example – “Rotax” is a registered trademark so a local class can use a Rotax engine with its own rules but it may not be called a Rotax class.

Why was a sealing system introduced?

The introduction of the Rotax Max engines in the late 1990’s changed the face of karting around the world forever! In the preceding thirty years little had changed in the design of 100cc air cooled, amazingly simple little engines, but the maximum RPM was now exceeding 20 000 and component life was expressed in minutes rather than hours! Sealing an engine like this served little purpose and three or more engines were used per event. The engines would need rebuilding and running in after each event so scrutineers affixed temporary seals or just marked the engines.

The Rotax Max kart engine was designed to deliver good and reliable performance for fifty hours between rebuilds and this was achieved mainly by reducing the RPM. The use of modern materials (like nikasil – ridiculously hard and durable cylinder coating), digital ignition and an exhaust power valve were introduced to increase the low-speed power, so you do not need to rev to extremes on top. Increasing the capacity to 125cc completed the formula. Similar performance to the extremely high revving 100cc was easily achieved and the goal of a long-life engine became a reality, and the engine sealing system was introduced in 1999.

How does the sealing system help to prevent cheating with engines?

Scrutineering in kart racing is important – you want to know that you have a fair chance – and in the good old days, scrutineers could simply strip several of the top placed air-cooled engines and check for legality – they were going to be rebuilt in any case, so it did not matter if you took it home in pieces. With the Max and the long-life philosophy, it is possible to seal the engine from new or after a rebuild and let the authorised Service Centre put his signature on it (the Rotax bar coded seal) as an undertaking that it conforms to the regulations. Naturally checks can still be done at a race to ensure that the Service Centre is doing his job properly, but it reduces the need to open every engine after a day’s racing. Clearly you would not want to take your engine home in pieces in a box after every event – the only option of fairness without the Rotax sealing system. Many competitors will do full season or more in the lower classes with the same seal in place!

Why are only Rotax accredited Services Centres allowed to seal engines?

Rotax Service Centres are vetted by the distributor, have a qualified mechanic doing the work, using the correct tools, and fitting only original BRP Rotax parts. There are absolutely no modifications allowed and so a carefully assembled motor with the correct clearances from any one of the Service Centres should deliver great performance over an extended period. Each seal is registered with a specific Service Centre, so traceability is ensured.

How can I be sure that my engine is prepared to the highest standards?

We have always tried to ensure that every chassis brand has at least one service centre that it is happy to use. All Service Centres will offer you their service and there are no sealing rights granted to anyone to run only one or two competitors. In the past 20 years we have only found one service centre guilty of breaking a regulation – despite dozens of strips at regional and national championship events. A list of authorized Service Centres is published on www.kart.co.za and names may be added or removed from time to time as the market changes.

Spend more time on the track and less time in the workshop! There is so much more to adjust outside of the engine – gearing, carb settings, tyre pressures and the all-important chassis set up is a science on its own! Mojo tyres allow you to enjoy more laps while also providing a tightly controlled level playing field.

Where else in the world is this system in place

Globally 43 Rotax Distributors look after the RMC series in more than 100 countries with approximately 700 accredited Service Centres all with one set of rules!

For more about the Official Rotax Max Challenge visit www.kart .co.za.

Happy MAXing!