Moto GP Class Engine Moto Race Championship

Moto GP Championship - New specifications for each racing class are formed as the FIM sees fit. On beginning of  new Moto GP era in 2002, 500cc two-stroke or 990cc four-stroke bikes were specified to race. Enormous power advantage of larger displacement four-stroke engine over the two-stroke eliminated all two-strokes from competition; on following Moto GP season no two-stroke bikes were racing. In 2007  maximum  capacity was reduced to 800cc without reducing  existing weight restrictions.

Moto GP Championship - class race bikes are not restricted to any specific  configuration. However, the number of cylinders employed on engine determines  bikes's permitted minimum weight; weight of extra cylinders acts as a form of handicap. This is necessary because, for a given capacity,  more cylinders is capable of producing more power. If comparable bore to stroke ratios are employed, engine with more cylinders will have a greater piston area , a shorter stroke. Increased piston area permits an increase in total valve area, allowing more air or fuel to be drawn into engine, shorter stroke permits higher revs on same piston speed, allowing to pump still more air or fuel with an potential to produce more power, but with more fuel consumption too. In 2004 bikes were entered with three-, four-and five-cylinder configurations. A six-cylinder model was proposed by Blata, but it did not reach the Moto GP grids. Presently four cylinder engines appear to offer best compromise between weight, power, fuel consumption as all competitors on 2009 series use this solution in either 'V' or in-line configuration.

In 2002, the FIM became concerned on advances in design as in engineering that resulted in higher speeds around of race track. For purposes of increasing safety, regulation changes related to weight, amount of available fuel or engine capacity were introduced. Amended rules reduced engine capacity to 800cc from 990cc , restricted amount of available fuel for race distance from 26 litres in year 2004 to 21 litres in year 2007. In addition, minimum weight of 4 cylinder bike used by all participating teams was increased by 3 kg.

Highest speed record for a Moto GP is 349.288 km/h (217.037 mph), set by Dani Pedrosa riding a Repsol Honda RC212V 800cc during Free Practice 1 at the 2009 Italian Grand Prix.

On December 11, 2009, Grand Prix Commission announced that Moto GP Championship engine class race would return to 1000 cc limit starting with 2012 season. Maximum displacement will be limited to 1000 cc, maximum cylinders would be limited to 4, maximum bore would be capped at 81 mm. Carmelo Ezpeleta indicated that projected changes were received by the teams favorably.