MIKE BROWN’S YAMAHA YZ250 TWO-STROKE: PREMIX VIDEO SERIES

Mike Brown has raced at the highest level of motocross, Supercross and off-road for factory-level teams during a career that has spanned over three decades. The 47-year-old racer is no longer competing to put food on the table, but is now doing selected events for Yamaha, FXR and Rockstar Energy just for fun. We talked “Brownie” into signing up for the Wiseco Two-Stroke World Championship at Glen Helen Raceway with the promise of good times and a fun bike to race.The Yamaha YZ250 two-stroke platform hasn’t changed very much in the last decade and a half, so finding parts for the build was not a problem. Brown told us in the very beginning that he would prefer a bike that produced usable power rather than explosive power. So, this became the foundation for our build. Our 2019 Yamaha YZ250 test unit was sitting at the Dirt Bike headquarters just begging to be raced, so work began immediately. The bike basically being brand new saved us a lot of time. The engine wasn’t drastically changed internally. We did install a Rekluse Core Manual TorqDrive clutch and CNC-machined billet-aluminum clutch cover. The TorqDrive system is designed to provide the ability to fine-tune the transfer of power to the ground. Rekluse does this by using more disks in the same amount of space, so up to four additional friction disks are allowed to be used compared to the OEM unit. More friction plates means more torque capacity translating into more power transferred directly to the rear wheel. To further fine- tune power delivery, Rekluse offers a variety of different spring options that can be combined for a completely custom feel, depending on the rider’s preferences. The stiffer the spring setup is, the more torque is transferred to the rear wheel, but that makes the clutch pull harder as well. We settled on a slightly stiffer-than-stock clutch pull that allowed more torque transfer.

For the complete story on our Mike Brown Yamaha YZ250 two-stroke project click the image below!