PUCH MC 250 Twin Carb
PUCH MC 250 Twin Carb (photo: Stephan LeGrand)
2T engines, until recently, could have two different types of intake: in the cylinder (the piston fulfilling the function of inlet valve or in the crankcase (through a rotary valve attached to the crankshaft or, optionally, through a lamellar inlet in the center crankcase).
It was accepted that cylinder intake favored the power band and that rotary valve favored maximum power. For this reason, engines designed for off-road use usually used the first solution, while the second option was more usual in terms of road racing.
Harry Everts and the PUCH MC 250 Twin Carb, the lethal combination that resulted in the Belgian first of 4 and Austrian builder's first titles (photo: Chris Malam)
In 1974, Austrian manufacturer PUCH hired Harry Everts to ride an innovative motorcycle with which he reached third position in the Motocross World Championship in the 250cc class. The following year, at the controls of the final stage of the same bike, Everts became World Champion, a feat of enormous importance, especially considering the small industrial dimension of PUCH compared to its rivals.
The bike had several refinements typical of a factory bike, such as the use of magnesium in the engine crankcase and in the wheel hubs, but the feature that made it truly unique was the fact that it had dual intake through two BING 32mm carburetors. , one through the cylinder and the other through the rotary valve! The two systems were designed to work together to create a wide power band. The engine claimed a maximum power between 42cv and 51cv, according to the sources! Regardless of these facts, everyone agreed in considering this bike a real rocket, the abundance of power from this engine made it very demanding from the driving point of view and a good level was necessary to extract the juice from this set. In 1976, PUCH marketed a (true) replica of the Everts motorcycle that would have had a production of about 100 units and that, due to the refinement of all the materials and finishes, was practically a factory motorcycle.