Set of parts and transformation (Rayer Kit 350) enabling the power of a two-stroke Trialty 250 Yamaha engine with valve admission to be increased

摘要

This set of detached parts and transformation (Kit 350) enables the performance of a TY 250 Yamaha motocross competition engine to be enhanced. It comprises: - a cylinder 1 designed with a new liner 2 equipped with a different timing diagram 3 as well as increased cylinder capacity enabling much more power and torque to be obtained available at all engine speeds without detracting from the engine's reliability; - an adjustment operation 4 between the two main engine sumps and the base of the skirt of the new cylinder liner (greater); - a cylinder head 5 with a hemispheric chamber of different taper; - a complete piston 6; - a pre-set carburettor 7 with a greater passage diameter. The invention can be used for enhancing the performance of a TY 250 for competition. It can be used as a basis for developing and marketing a new motocross engine of Yamaha or other make.