New YZ250X Off-Road Racer Is The Big News!
Yamaha is serious about off-road competition and is showing it with a two-stroke entry into the class–the new 2016 YZ250X. Heavily influenced by the YZ250 motocrosser, it has exactly what you’d expect in the way of alterations to become an off-road racer, some that are difficult if not impossible for the regular Joe to do on his own. And maybe not enough changes when compared to some other brands, but it is all subjective.
The bike is 95% motocrosser with the usual modifications. An 18-inch rear wheel, side stand, O-ring chain, altered suspension settings and re-tuned engine–the clincher a five-speed wide-ratio transmission. Though not as drastic as some had hoped, it is a start from the Japanese company to get back into the two-stroke off-road racing game.
Inside the engine the compression ratio is dropped slightly and the activation of the powervalve, through the ramp and springs is tuned specifically for drivability and to be smoother and have a more torque feeling than the motocross bike. The transmission ratios are closer in first through third gears then fourth and fifth take big steps forward in spacing so the bike is difficult to actually top out. A ride on the bike will be needed to see if Yamaha’s thinking and application is correct on this.
If the YZ250FX is any indication the Yamaha crew have a pretty good handle on getting the suspension correct right out of the box with an aggressive off-road racing setting that can still do work on a motocross track if needed. The components are identical to the motocross bike save for internal settings. Additional changes include a fuel petcock with a reserve setting (the tank capacity is the same as the motocross bike) and an exhaust pipe of identical dimensions but turned and tucked in tighter to minimize dents and dings.
It may not be the rumored YZ300X that has been getting play around the internets, but it is a safe start in that direction using an existing platform to judge the market. The YZ250X is priced at $7390 and will be available in August.
The four-stroke motocross bikes get some revisions as well, especially the YZ450F. It has an all-new frame with a noticeably larger footpeg/swingarm plate to increase rigidity. That along with thicker and larger engine mount hangers and triple clamps with 2mm more offset (from 22mm to 25mm) has all combined to settle the YZ down and allow the rear of the bike to have a more planted feeling according to test riders. Even the rear shock spring is one rate lighter, which is seeming a trend across brands in 2016. 
The YZ450F engine gets a few small changes to the clutch boss surface, some shift-stop and torsion spring changes, a slightly altered cam timing and a drilled water pump impeller. But the big news is the addition of launch control to the ECU and it is said to operate on a completely different theory than any other system out there. Test rider’s were very positive about it and claimed they used the feature every time they did a racing start no matter the surface, it is claimed that good.
The YZ250F returns with it’s current frame and some of the same small changes to the engine as the YZ450F but not the launch control. Additionally it gets a few treatments to the crank and rod, better oil spray for better durability and what Yamaha calls “less noise” meaning reduced vibration through better balance especially at high RPMs. The ECU is also altered for a better sign-off at redline RPM. It does not get launch control. There are the usual suspension improvements and on both bikes the jump to a 270mm front disc rotor.
Since 2016 marks Yamaha’s 60th anniversary there will be an additional limited edition Yellow and Black YZ available, making for three different standard color combinations for YZ motocrossers. 
