Related: 2024 Dirt Rider 250F Motocross Bike Comparison ... an FMF Factory 4.1 RCT slip-on titanium muffler, which helps its fuel-injected liquid-cooled DOHC four-stroke 250cc single-cylinder ...

If you've ever attended a Motocross race and heard the throaty growl of powerful four-stroke dirt bikes as the riders ...