Easily one of the most intriguing bikes to come out of the factories in 2014, the Yamaha YZ250F is a monumental step forward in the evolution of the YZ250F. The first modern-day 250 four-stroke, the 2001 Yamaha YZ250F, was an engineering marvel. It revolutionized a class previously owned by 125cc two-strokes. Yamaha is one of the main reasons four-strokes now hold court in motocross (of course, the AMA’s generous size displacement for four-strokes was the nail in the two-stroke coffin).
In hindsight, Yamaha hit a home run with the YZ250F. How different the market would be in 2014 if the 2001 YZ250F hadn’t been accepted by the consumer or if the bike had suffered from mechanical issues. Instead, the YZ250F was ironclad tough and considerably easier to ride than any 125 two-stroke. Other manufacturers followed the four-stroke path several years later—building on the groundwork that Yamaha had laid. So while many early 250 four-strokes had teething issues, Yamaha proved that they could be reliable.
For many years, the MXA wrecking crew was puzzled by Yamaha’s lackadaisical approach to updating the YZ250F. The blue crew had been ahead of the four-stroke curve for so long, but they chose to rest on their laurels, and that allowed the competition to catch up. In short order, other 250 four-strokes surpassed the YZ250F in terms of performance and technological advancement.
It originally appeared that Yamaha would swing for the fences in 2010. They revised their perimeter aluminum frame to straighten the intake tract (a must-do for electronic fuel injection). They pumped up the engine and designed a flat-bottom fuel tank, which made installing a fuel pump easier. They wisely kept the proven Kayaba SSS suspension. Sadly for the times, the 2010 YZ250F came with a Keihin carburetor (an unpopular move in the court of public opinion), and the engine wasn’t massively improved. It was just more of the same for the 2010 YZ250F.
The MXA wrecking crew finally got its wish in 2014. Yamaha stepped up to the plate and delivered an all-new YZ250F with all the technological advancements mated to the already proven equipment. If you’ve read our 250 shootout, then you’re aware of our glowing approval of the direction that Yamaha took. It was barely edged out by the Kawasaki KX250F. Why? The powerband isn’t quite as sweet as the KX250F’s, plain and simple.
The MXA wrecking crew embarked on a journey to build a 2014 Yamaha YZ250F that would top the 250 class—and do so with force. Of course, we couldn’t help but pay homage to Yamaha’s illustrious history. Cycra Racing dialed us in with a complete set of retro butterscotch-yellow plastics. Dubya provided gold wheels (just like works Yamaha bikes of the late 1970s), silver spokes and black carbon fiber hubs. Details, such as engine plugs and axle blocks, were handled by Works Connection. We buttoned up the aesthetics with custom Factory Effex graphics and a seat cover.
Though our YZ250F project bike harks back to the glory days of Yamaha, there’s more than meets the eye. Underneath the plastics kit is a Hinson slipper clutch, Twin Air Powerflow air filter kit, and a DR.D exhaust system. We figured that Doug Dubach, chief test rider at Yamaha, would know what the YZ250F needed to bolster performance.
Since 2006, we’ve gushed about Kayaba’s SSS suspension. Having said that, we shipped out our YZ250F forks and shock to Graeme Brough. It sounds preposterous to mess with success, but Yamaha beefed up the spring rates for 2014, making them too stiff for light riders (they have fixed this error for 2015). We had Graeme swap the springs and change the valving specifically for our smaller testers. Given Brough’s excellent track record, we knew he was the guy to improve on the already superb suspension.
What was the total cost of our bike build? Since our plan was to build the ultimate YZ250F, the MXA wrecking crew doesn’t worry about money. We want to show what is possible and you don’t have to do everything we did —but we want you to see all of the option. That said, we spent several thousand dollars, but it was worth every penny. Not only did we vastly improve the YZ250F powerband without sacrificing durability, but we also fixed flaws in other areas. An oversized Moto-Master front brake stopped us in our tracks. A Ride Engineering longer link arm helped balance the suspension and keep the shock from blowing through the initial part of the stroke. Then there were the sweet Cycra plastics and accompanying anodized parts that were attractive and sharp-looking.
We love the power and layout of the 2014-15 Yamaha YZ250F. We could live happily ever after with the stocker, but what fun would that be?