Check out our First Ride video at http://www.motocross.com/features/first-ride-video-2012-yamaha-yz250f/.
We made our way out to Glen Helen to check out Yamaha’s highly revised new 250F. It was a treat to see the many new changes as well as one feature we thought might be a thing of the past… That’s right, we were hoping for fuel injection. Changes were made where they were due and the 2012 YZ250F saw some revisions in the engine, carburetor, suspension and the chassis.
Starting with the skeleton of this machine, the tank rail, swingarm pivot, engine brackets and the swingarm itself have been changed for increased rigidity. In the power department we have a new lighter piston with a ribbed configuration that helps reduce the reciprocating mass and friction. Also on the inside, the YZ250F received a different crankshaft for reduced vibration as well as improved durability. The balancer shaft and weight were redesigned to work with the lighter piston. Revised CDI settings round things off to accommodate the many changes made to the engine.
The fork offset was changed from 25mm to 22mm and the top triple clamp has four adjustable positions. The fork and shock were revalved to match the changes to the chassis and the fork went one spring rate stiffer from .45kg/mm to .46kg/mm. The overall rigidity of the fork has been increased by 50 percent. Revisions to the shock include revised rebound damping and a shorter shock shaft. The goal here was to improve bump absorption and refine the damping characteristics.
Yes, that is a carburetor but don’t get discouraged! Yamaha went big and jumped from a 37mm carb to a 39mm to increase top end performance in the higher rpm range. And to make the bike breathe better, a bigger air filter cage was added.
The silencer now has a smaller outlet by 8mm and will pass the AMA 94 db regulations.The biggest thing we noticed was a stiffer, more solid feeling bike with precise handling. Yes, even more precise than last year, because last years bike handled great on a smooth track. At the end of the day on a beat up Southern California track such as Glen Helen or Racetown the ’11 would begin to struggle in the bigger bumps. Yamaha stiffened up the entire bike by making many changes to the chassis as a whole and achieved a smooth yet planted feeling. Riding Glen Helen at the end of the day when the track was hammered was a good test to show us how well these improvements actually worked. The harder you ride the new Yami, the better it works.It was a surprise to us to see a carburetor on the YZ250F for another year, but we gave it a fair chance and it actually worked pretty well. You can definitely tell the difference between a carb bike and a F.I. bike in the way you ride them, especially when you switch back and forth and aren’t used to that slight hesitation of carburetion. I noticed very slight bogging on the usual hard landings and G-outs but also when adjusting the pitch of the bike in the air. You know when you hit a jump and let off in the air, and then whack the throttle to keep the front end from dipping? I got it to hesitate a few times doing this so we leaned out the fuel screw by a quarter turn. This eliminated the slight bog in the air and really helped the bog on harsh landings, but it was still present at times.Although it is the last 250F to remain carbureted, everything else is up to date and works like its suppose to. Making your bike work on a rough track can be a nightmare, but you don’t have to worry about that because the boys in blue have already done it for you. If the track gets rough on shootout day then the YZ250F will have an advantage, so check out a future issue of Dirt Rider for a more in depth test on the 2012 Yamaha YZ250F.
