High performance YZ250F-based engine
The YZ250F has proved to be one of the most competitive motocross bikes at every level. US rider Aaron Plessinger won the 2018 AMA Pro National 250MX series and the model once again dominated in AUS by scooping both the 2018 MX2 Nationals with Wilson Todd and the MXD class with Bailey Malkiewicz. This success is reflected in the off-road racing world with Luke Styke the reigning 250cc class Australian Off Road Champion.
The new WR250F engine is based closely on the winning fuel-injected YZ250F design, and features a rearward-inclined cylinder and reverse cylinder head. Its airbox is situated in front of the rider and the fuel tank located at the centre of the bike ‰ÛÒ a unique configuration that contributes to the bike's mass centralisation, which plays a pivotal role in achieving light and agile handling.
In addition, the WR250F's reverse cylinder head allows the use of a straight air inlet for higher levels of intake efficiency, and by locating the fuel tank centrally, this innovative design permits the use of a long and flat seat that allows the rider to shift their body weight quickly and easily.
The 2020 WR250F features a new high compression forged aluminium piston, revised valve angle and exhaust cam timing with revised balance factor ‰ÛÒ all based on the current YZ250F, but with enduro specific settings to provide a high level of winning performance. That performance is further boosted by the fitment of a dual electrode spark plug and revised exhaust muffler for 2020.
Compared to the former WR250F engine, the 2020 design is more powerful at higher rpm, and also delivers stronger power right through the rev range, making it a serious contender for top honours.