MOTO3 REGS for the 125 replacement class were released at Valencia, with the GP Commission finalising technical regulations for the 250 single-cylinder four-strokes.
The new series, due to start in 2012, restricts maximum bore size to 81 mm. Other rules include:
A rev limit of 14,000 rpm
Eight engines per rider for the full season.
A maximum of four valves, and a single ignition driver. Variable-length inlet tracts are not allowed.
Hydraulic or pneumatic valve systems are banned, as are fly-by-wire throttle systems
Camshaft drive must be by chain rather than gear.
Variable valve timing or valve opening are banned.
Direct injection is not allowed, and fuel pressure maximum is five bar.
The maximum price of the engine, including special parts or service contracts, is 12,000 euros.
Engine manufacturers must be prepared to supply a minimum of 15 riders.
Engine updates or upgrades must be available to all customers at the same time.
Six gears maximum, with a maximum of two alternate ratios for each gear. Two alternate primary drive ratios are permitted.
A control ECU will govern ignition and fuel injection, and include a rev limiter. Tuning options will be included in the supplied software, and the organisers can swap ECUs at any time; standardised data-logging systems must be used.
Chassis must be prototypes, with a minimum total weight of motorcycle and rider of 148 kg.
Carbon brakes are banned, as are active and semi-active suspension systems, which must use steel springs.