The Yamaha YZ250FX was first introduced in 2015 and has received many of the same updates the YZ250F motocross bike has since then. The main off-road-specific components on the YZ250FX are a wide-ratio six-speed transmission, cross-country suspension settings, a 2-gallon fuel tank, a plastic skid plate, a kickstand, an O-ring chain, an 18-inch rear wheel, and Dunlop AT81 tires.
This engine runs very well for its application. In tight or flowing single track sections, it’s very good with a smooth power delivery that is easy to ride, limiting you only by your own skill level. When the trail opens up or when riding a fast grass track, it feels like it could use a little more acceleration, but this is more due to the wide-ratio transmission than the engine lacking power. Finding additional power is easy as Yamaha offers GYTR engine kits consisting of a cylinder head assembly and high compression piston. There are also aftermarket companies that offer several options.
This YZ250FX uses the same six-speed wide-ratio transmission as the WR250F enduro bike. For off-road competition, the gap between the gears is a little further than I would like. In comparison to the YZ250F, it has a super low first gear that is only used in very tight situations. Second gear is a touch lower, third gear is equal, fourth and fifth gear are both taller, and there’s an additional sixth gear that acts as an overdrive. For today’s style of GNCC racing, gear ratios closer to the YZ250F transmission with the taller fifth and sixth gear would be preferable. For long rides or long distance racing, the sixth gear works great.
The clutch is good and has minimal fade, unless you abuse it, such as when leaving the bike in third gear in tighter situations instead of shifting down to second. From personal experience, the stock two-gallon gas tank has lasted well over two hours of riding and covering 40 miles without an issue while racing.
Suspension And Chassis/Handling
The KYB suspension is extremely plush and ready for tight trails and rocky conditions. If you are an intermediate-level rider or above and weigh more than 170 pounds, you will want to invest in some stiffer springs for the front and rear as just stiffening the clickers with the stock springs will likely not be enough. Depending on the riding conditions, I can say from personal experience that going up one spring rate and then adjusting the clickers works well. One thing Yamaha does not mention is the shock is slightly longer than the YZ250F motocross bike. To our understanding, it was made longer to allow more clearance for the electrical and battery box when the suspension is fully compressed. Because of this, you may get a slightly high rear end feeling at first. Lowering the sag approximately 3mm to 4mm from what your regular setting would be should bring things right back to normal, and we found good results with 105mm. The 270mm front brake works well and has a progressive feel.
The YZ250FX is a very good off-road racebike. Its strong engine and stable chassis make it a great choice for the serious off-road rider. At a price point of $7,999, it’s also a great value. It’s fun to ride and has good versatility. You can easily take the bike to the motocross track one day, trail ride it the next day, and then race it at an event like a GNCC or hare scramble on the weekend.
|ENGINE||250cc, liquid-cooled, single-cylinder four-stroke|
|FRAME||Aluminum bilateral beam|
|FRONT SUSPENSION||KYB Speed Sensitive System (SSS) coil-spring fork adjustable for compression and rebound damping; 12.2-in. travel|
|REAR SUSPENSION||KYB shock adjustable for spring preload, high-/low-speed compression damping, and rebound damping; 12.5-in. travel|
|FRONT BRAKE||Nissin single 270mm disc w/ twin-piston caliper|
|REAR BRAKE||Nissin single 245mm disc w/ single-piston caliper|
|SEAT HEIGHT||38.0 in.|
|FUEL CAPACITY||2.0 gal.|
|CLAIMED WEIGHT||249 lb. wet|