The Spi 7x26x7 seal (ref. 230195) Provides the critical separation between the cooling circuit and the gnattern crankcase. Positioned on the water pump shaft, it ensures that the coolant remains in the engine and the box oil is not contaminated by water. Perfect sealing at this level is vital to avoid engine overheating or an oil emulsion (the famous "mayonnaise").

The Thunder-end needle cage (often referenced under the norm Hk1010, Ref. Rotax 232460) is a small needle bearing housed in the engine housing or launcher support. It receives the end of the electric starter shaft. Its role is crucial: it allows the tree to rotate at very high speed during the start phase with a minimum of friction, while supporting the radial stresses during the haling.