Following the announcement of the Rotax EVO engine upgrades there has been much speculation and opinion flying around the Karting World. BRP-Rotax have never introduced any changes that completely obsolete previous production engines or components. The Rotax Max EVO range of engines is designed to be the basis of future production for the next 15 years. The MAX has already enjoyed a unique level of success for fieen years. With the inclusion of modern technology the EVO has a brought new features to Kart engines never seen before.
The new Dellorto electronic ignition system allows for improved ignition performance and an electronically controlled Exhaust (Power) Valve on Senior and DD2 models. This will ensure the constant and controlled opening and closing of the Exhaust Valve without any influence from the Exhaust system itself. This won’t improve the ultimate performance but it will greatly improve the engine’s ability to perform consistently. By the same token the new ignition system will improve the ignition curve to help the engines combustion to perform more consistently. This will work with the new specification VHSB 34 XS Carbureor which is a complete rethink on the existing QD and QS carbs in use today. The new carbureor has a similar body and a 12.5 Venturi. However an old type QD or QS cannot be upgraded to XS specification. If you want to get the right Rotax Max jetting then click the link
The internal machining of the body is significantly different. The factory have done extensive testing to arrive at the new specification which allows for consistent performance with very lile variation to jet sizes. The new carb will run with a jet around the 125 mark. The need to change jets will be reduced to almost nil. Due to the time of year when the EVO range was introduced, JAG Engineering and the MSA agreed that the best time for introduction into the UK market would be 1st January 2016. It was decided that for maximum stability it would be beer to hold off until 2016 to allow for the products to sele into the European market and minimise any on cost to customers.
BRP- Rotax have pledged to supply MAX COLUMN existing pre-EVO engines and accessories for the foreseeable future, it has also been agreed to supply upgrade kits at subsidised prices for those wishing to convert their engines to use with EVO accessories. There is no hard evidence yet that the Rotax Max EVO engines or upgrades will in fact be faster. Yes they have the potential to be easier to use, easier to Jet and use less fuel, but faster? The jury is definitely out at the moment. The delayed introduction in the UK is the best possible solution for our extremely strong customer base. This gives us plenty of time to do dyno and circuit testing to truly evaluate all the changes and how to stage their introduction into the market.