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2001 YAMAHA YZ250 still shot

WE TEST THE 2001 YAMAHA YZ250


Yamaha was the first motorcycle manufacturer to figure out that it’s not how much power you make, but how you make it.

YAMAHA YZ250 TWO-STROKE JETTING (1999 TO 2014)


Be the brass master general

YAMAHA DEBUTS THE YZ250F


Amidst all the hype surrounding the first outing of Honda’s RC450, Yamaha also debuted a new bike at the October 22nd race in Japan. That’s right, at the same mud race where Tortelli showed the world the RC450, Ernesto Fonseca proved to the world exactly what the YZ250F was capable of after months of rumors. Ernesto holeshot both motos and after a small battle with the locals, pulled out to a ten second victory in moto one and a twenty second victory in moto two. On hand at the event was the very proud …

YAMAHA’S ALL-NEW 250 FOUR-STROKE


Believe it or not, Yamaha will race a four-stroke in the 125 class next year. No, not a 125cc four-stroke—a 250cc four-stroke. Under current AMA rules the 125 class is limited to 0-to-125cc two-strokes and 0-to-250cc four-strokes. The all-new Yamaha YZ250F (the F stands for Four-Stroke) is a down-sized version of the popular YZ426 (which is 250 class legal). But do not think that the YZ250F is a clone of the YZ426. In fact, it shares very few engine components with its big brother. Few engine parts ar…

MXA’S SECRET JETTING SPECS, 2003 And Back


We can’t tell you how to jet your bike. It’s a big world out there (and we don’t know you all that well). However, we can tell you what jetting we run in the MXA test fleet. Take into account that we race in a Mediterranean climate, near sea level, within sight of palm trees and never far from a Double Latte. We also run fresh 92-octane gas, work on our bikes every week, clean the filters, change pistons and rings regularly, are alert to pinging and haven’t changed oil brands in over a decade. This is t…