Watch as we put the YZ-F though its paces on Glen Helen Raceway’s wide-open track in the 2012 Yamaha YZ250F First Ride Video.
After a major redesign in 2010, Yamaha elected to release the 2011 YZ250F virtually unchanged, but that doesn’t mean they took some time off. The 2012 YZ250F has been tweaked and refined so extensively it’s easier to call it a completely new machine than a revamped model. We spent a day at the iconic Glen Helen Raceway turning laps on the YZ-F and came away impressed with the handling and power improvements.
Taking a look at the 2012 Yamaha YZ250F you would be hard pressed to point out any differences from the 2011 machine, and we say that’s a good thing. The YZ-F is one of the best looking small-bore motocross bikes, especially in the Team Yamaha Blue and White color combination. Peel away the plastics and still the differences are not readily apparent. Most of the work is inside the engine and even
inside the frame.
In the ultra-competitive world of the Lites Class, giving up any horsepower to the rival team is a surefire way to lose races and customers. Last year we expounded the virtues of the low- and mid-range power of the YZ-F but we felt it left some HP on the table above 8000 rpm. For 2012 Yamaha turned its attention to increasing the power output in the upper rev range with a host of engine revisions.
Internal engine changes focused on reducing reciprocating mass and friction. A new lighter piston with rings that reduce friction has been matched to a lighter piston pin and clips to help free up some revs. The crankshaft, balancer shaft and balancer weight have been optimized to work with the lighter piston and reduce vibration passed onto the rider via the handlebar, seat and footpegs.
In addition to the internal enhancements, the YZ250F also gets a 39mm Keihin FCR carburetor, taking a cue from Star Racing’s 2011 playbook. To assist the with the flow of air into the 2mm larger fuel and air mixer, Yamaha fitted the YZ-F with a larger high-flow air filter cage. On the other end of the journey is a new silencer that conforms to the AMA Pro Racing 94 decibel regulations. Revised CDI settings are tuned to increase the top-end power.
What good is more horsepower if the chassis isn’t up to the task of allowing you to take advantage of the increase? Yamaha’s engineers turned their attention to stiffening up the frame for more consistent and predictable handling when the track gets rough. The upper frame rails have been changed from a two-box section to a three-box section to control flex. At the rear of the frame the cast swingarm section is all new, and the engine brackets have also been redesigned.
The front and rear suspension recieved spiffer springs to work with the more rigid frame, swingarm and forks.
Reworking the frame was the foundation for the all new parts that hang off of it. Up front the revalved Kayaba Speed Sensitive System Front Forks are now offset by 22mm rather than the previous 25mm, matching the it’s big brother YZ450F. The outer fork tube has been stiffened to work with the new rigidity of the frame, while the spring rate has been increased from .45kg/mm to .46kg/mm. Out back a new, less-flexible swingarm works the KYB piggyback rear shock which has been revalved and resprung. The unit now has a 46mm piston and a smaller 16mm shock shaft. Every one of these changes was focused on improving bump absorption while providing more control when the track gets rough.
Yamaha still offers the YZ250 in two colorways, but the $100 premium for black wheels and a gold chain is no more. Both the Team Yamaha Blue/White and the White/Red schemes come standard with the goods for the same $7250 price tag.
Once the tech presentation adjourned, it was time to throw a leg over the YZ250F to judge for ourselves if Yamaha had done its homework. Hopping on the Yamaha, the bike felt just like last year’s mount – not as small as to other
machines in its class. We see this as a good thing as it is more hospitable for medium to tall riders. The seat is nice and flat and allows for easy fore and aft movement. The tank and radiator width is thin and allows for plenty of grip with your knees while sliding up on the front of the seat. A set of massive footpegs and high quality ProTaper bars finish of the nicely laid out cockpit.
Once on the track, we immediately noticed the increase in engine power. The Yamaha pulls strong out of corners and continues to make power long after the 2011 model would have petered out. While some of our testers last year thought the power of the YZ was acceptable, most of us thought it was a dog. Not the case now, while it doesn’t feel as stout as the KX250F, we’ll reserve or final judgment when we have them all together on the same track. Even on the massive uphill sections of Glen Helen the YZ-F didn’t feel to be lacking any mojo.
“The biggest standout improvement over last year was power. The motor had much more hit with a ton of over rev! It was very smooth, which made it so easy to ride,” says our pro-level test rider Matt Armstrong. “There is a wide range of power where I could ride the bike a gear high in certain sections and the motor never felt like it was lugging.”
Fueling from the last of the 250F carburetors was spot on and as crisp as iceberg lettuce. Even when in too high of a gear the throttle response was immediate and did not bog. Landing hard on jumps never upset the fuel delivery as well. In fact, the uninformed would assume the YZ-F was fuel injected. How that would change a few thousand feet up from near sea-level remains to be seen…
Glen Helen’s long straights and steep uphills are notorious for putting strain on the gearbox and clutch, but the 2012 YZ-F never missed a beat. Even when the motor was in full-tilt mode pulling my 220-pound frame up the steepest of hills, gear changes were easy and drama free.
The altitude (elevation doesn’t even describe the size of Glen Helen’s hills) changes also provide ample opportunity to put the brakes to the test. Stopping power is more than adequate from both the front and rear with fade-free performance. I would like just a smidgen more initial bite, but I’m really nit-picking here.
As impressive is the newfound power of the YZ250F revised mill is, the handling is just as stellar. Right from the get-go we got along with the rear suspension. The rear end tracked straight and true no matter what we threw at it, and
Our pro-level test rider, Matt Armstrong enjoyed the predictable and consistent handling of the 2012 YZ450F..
handled big hits while still being plush in the chop. The fork complemented the rear suspension’s action almost perfectly, and kept the front end under control.
“The rear suspension was great right out of the box! It tracked so straight down the long, high-speed, rough sections and was very plush through the entire stroke,” says Armstrong. “And the forks were no different!”
Last year the YZ-F tended to plow if body positioning wasn’t on point, but this year we had no problem making the Yamaha turn and turn well. Immediately we were able to chose any line in any corner and make it work. Usually it takes me two to three laps to warm up and find my flow, but on the 250F it was more like three or four corners. Armstrong also came to terms very quickly with the handling and only returned to add a few clicks to slow the front rebound and mellow a slightly twitchy front end.
“Handling of the bike was very predictable and consistent which helped my confidence when throwing down some fast laps,” notes Armstrong. “It corners so easily, and I could put the front wheel where I wanted when I wanted.”
It didn’t take long for us to realize how much the YZ250F has improved over last year. Just about every gripe or negative we addressed in 2011 was remedied and improved upon for 2012. Overall we were very impressed with the YZ-F’s power increase and sure-footed handling. When shootout time rolls around, don’t expect the YZ250F to be in the back of the pack this year.