+ Well come to channel : I Love MotoGP https://www.youtube.com/channel/UCIvjKrJvTWD8VV3xMUWb9RA https://www.facebook.com/ilovemotopg/?modal=admin_todo_tour Grand Prix motorcycles are purpose-built racing machines that are generally unavailable for purchase by the general public or able to be ridden legally on public roads. This contrasts with the various production-based categories of racing, such as the Superbike World Championship and the Isle of Man TT Races that feature modified versions of road-going motorcycles available to the public. The championship is currently divided into three classes: MotoGP, Moto2 and Moto3. All three classes use four-stroke engines. In 2010 the 250cc class was replaced by the new Moto2 600 cc four-stroke class. In 2012 the 125cc class was replaced by the Moto3 250cc four-stroke class with a weight limit of 65 kg with fuel, and the engine capacity for MotoGP increased from 800 cc to 1,000 cc. Previously, the championship featured a 50cc class from 1962 to 1983; an 80cc class from 1984 to 1989; a 350cc class from 1949 to 1982; and a 750 cc class from 1977 to 1979. Unlike races such as the TT Formulae, or Moto-Cross, where two and four strokes had different engine size limits in the same class, until 2002 GP racing set the upper limit the same for both types of engines in all its classes. After that, MotoGP gave the four-strokes a 490cc advantage over the two-strokes. A 2 stroke engine produces power with every rotation of the crank, where as the 4 stroke engine produces power every second rotation. In theory, a 500cc 2stroke produces the same power as a 1000cc 4 stroke, however there are many differences between the two configurations. Carburation vs fuel injection, engine mapping, power/torque curves, and throttle response are a few major differences. Practice showed the 4 strokes generating 10 to 15 more Hp and turning in much faster lap times than their 2 stroke counterparts. 4 stroke engines would be the obvious choice for years to come. Moto2 and 3 are four-stroke only. A FIM Road Racing World Championship Grand Prix was first organized by the Fédération Internationale de Motocyclisme in 1949. The commercial rights are now owned by Dorna Sports, with the FIM remaining as the sport sanctioning body. Teams are represented by the International Road Racing Teams Association (IRTA) and manufacturers by the Motorcycle Sport Manufacturers Association (MSMA). Rules and changes to regulations are decided between the four entities, with Dorna casting a tie-breaking vote. In cases of technical modifications, the MSMA can unilaterally enact or veto changes by unanimous vote among its members.[4] These four entities compose the Grand Prix Commission. There have traditionally been several races at each event for various classes of motorcycles, based on engine size, and one class for sidecars. Classes for 50 cc, 80 cc, 125 cc, 250 cc, 350 cc, and 500 cc solo machines have existed at some time, and 350 cc and 500 cc sidecars. Up through the 1950s and most of the 1960s, four-stroke engines dominated all classes. In part this was due to rules, which allowed a multiplicity of cylinders (meaning smaller pistons, producing higher revs) and a multiplicity of gears (giving narrower power bands, affording higher states of tune). In the 1960s, two-stroke engines began to take root in the smaller classes. In 1969, the FIM — citing high development costs for non-works teams — brought in new rules restricting all classes to six gears and most to two cylinders (four cylinders in the case of the 350 cc and 500 cc classes). This led to a mass walk-out of the sport by the previously highly successful Honda, Suzuki and Yamaha manufacturer teams, skewing the results tables for the next several years, with MV Agusta effectively the only works team left in the sport until Yamaha (1973) and Suzuki (1974) returned with new two-stroke designs. By this time, two-strokes completely eclipsed the four-strokes in all classes. In 1979, Honda, on its return to GP racing, made an attempt to return the four-stroke to the top class with the NR500, but this project failed, and, in 1983, even Honda was winning with a two-stroke 500 #Motogp2018