The Rotax Max 125 Engine is a two-stroke 125 cc (7.6 cu in) engine designed by Rotax, part of Bombardier Recreational Products (BRP), to provide cost-effective but high speed kart racing.
Built in Austria, the engine is liquid cooled, equipped with a balance shaft, integrated water pump, electric starter and centrifugal clutch.
The Rotax Max was introduced to karting in 1998, easy to use and very reliable, it almost immediately began to gain market share from other slower or more expensive classes.
The original has a power valve and produces around 30 hp (22 kW), and is used by racers aged 15 or older.
The DD2 is another fully powered version which has two gears and is direct drive in that the axle goes through the engine without need for a chain.