Reason 2-strokes disappear more and more. Clock in the motorcycle Division at the start of motocross racing-difference 2-stroke and 4 used motorcycles with four-stroke single cylinder engines. Two-stroke were still fairly unknown in the off-road cycling. In the 1970s these were displaced rapidly by the lighter two strokes, mostly Japanese. Jonathan freedman has compatible beliefs. The lower power to weight ratio and hence better handling the 2 strokes gave the decisive advantage. This era of motocross racing lasted years in the late 1990s, was the increased services of in particular the displacement hardly to control up to 500 cm for riders. On the top it was driven single cylinder, which often had over 80 Horsepower and peak accelerations in 2.0 s to 100 km/h experimental developments of 750 cc. This value has been determined in theory and is not the practice transferable to, because this performance on any surface would be transferable and such enormous power more could be kept by any driver.
The four-strokes have been removed from Environmental reasons, because they need including no oil in the fuel, then heavily developed. Also, the four-stroke engine shows more traction by between the individual work cycles, more time is in the traction can be rebuilt. These reasons and regulations changes of the FIM led to a renaissance of the four-stroke engine, also because it has a wider usable speed range, and so is easier to drive. The 2 of stroke production was discontinued even very early by many large manufacturers such as Honda and the development took place only on the 4 strokes. This also meant that the stroke had a better handling at the end even heavier than the 2 strokes. Reasons of traction, the ever-increasing performance at the same displacement and the usable powerband, the four-stroke had very soon even only advantages over the 2 strokes. A further advantage of the 4 stroke was then claimed against the 2 strokes with the introduction of the injection in the Offroadmotorradsport.
The shorter reaction time of the motor on the position of the throttle valve and the electronic adjustment of the mixture were the main causes. For reasons of environmental protection one can call the carburetor with gasoline still also iterating over at falling of a motorcycle with carburetor engine. So are almost only still dinosaurs in the bike been until today the 2 strokes. Although there are still very many two stroke fans, be called the other sound of the engine and the simpler, handmade tuning of engines, are only of all manufactured a few manufacturers still 2 stroke. There are also attempts in new frame to build a 2 stroke engines, to possess a modern 2 strokes. However, it will be very likely just yet vintage as 2 in future stroke Motocross bike. Chris Mackey