As many people already know, Yamaha’s innovative thinking started way before the YZ400F was introduced. The company began radically changing bikes as far back as 1972, when it pioneered the first production reed-valve system. Some of Yamaha’s other groundbreaking ideas include the first works water-cooled bike, first production monoshock and first production power valve. With that being said, we are always curious to see what Yamaha has up its sleeve for the next year.The ’03 marks the first real face-lift the YZ250F has received since its introduction in ’01. The ’03 YZ250F looks and feels ergonomically much closer to its YZ two-stroke cousin. In the process of creating this new environment, Yamaha redesigned the YZ-F’s seat, fuel tank, side covers and rear fender for improved rider mobility. The frame was strengthened and shaved of any unnecessary weight. Following the ever-popular weight-loss trend the sub-frame is constructed of square pipe. By integrating the rear brake’s reserve tank with its master cylinder, the new 250F lost 45 grams and gained some improved feel. Even the swingarm was able to shed some excess weight thanks to a new smaller, partially hollow design.A new triple-clamp design was implemented to aid overall stability. Fork- and shock-setting changes were applied to obtain a plusher ride. An automatic decompression governor system was added in the engine department for hassle-free starting. Relocation of the hot-start button to the handlebars makes on-the-track starting easier in case you stall. In the quest for higher quality, the crankshaft was redesigned for more reliability. A new oil-circulation system was installed, and it, along with lowered overall oil volume, provides even more weight loss. To gain more horsepower, pumping loss was reduced and carburetor settings were altered. When you can combine two systems into one, weight savings are an obvious side benefit. The YZ-F’s new Direct Ignition Coil is a perfect example. Similar to the system used on streetbikes, the ignition coil was integrated with the spark plug cap — trimming off 110 grams. Last but not least the CDI unit is smaller and relocated.On the Track!
Last year’s YZ250F topped our list of favorite and most ridden bikes in the stable. To no surprise, kicking over the bike without having to use the decompression lever put smiles on our faces. With less weight, new ergos and a little snappier power, the ’03 YZ250F still feels very similar to its old self. But that’s a good thing. The new ergonomics received almost instant praise from our testing crew. The flattened seat-to-tank ratio allows the rider to be more aggressive in corners and adds overall comfort. The only hitch we found was the seat — it felt as if it had a coat of Armor-All on it. Fortunately this was a quick fix with a grippier seat cover.Yamaha hasn’t left one area overlooked for excess weight, making the little four-banger feel lighter and more nimble than ever. The lost ounces shaved from the entire bike took off a little more than six pounds total. The new front and rear brakes offered plenty of stopping power and never faded in long motos. The 250F handles so well that during development the new YZ450F was targeted for the same track mannerisms as its little brother. The Yamaha was very stable and predictable, never acting up on even the roughest course. After some minor tuning, we got both the Kayaba fork and shock feeling plush in braking and acceleration bumps while still allowing the bike to keep putting power to the ground.The motor department made slight gains in the bottom and mid but still maintains its wide powerband. While testing at Piru Motocross track, our heavyweight tester Jason “Big Mac” Webb commented on his ability to clear jumps from the inside, which would be impossible for him on any of the 125s. The engine has good throttle response off the bottom and comes alive with a strong midrange, yet it has good overrev without running out of power unexpectedly.In stock form, the YZ250F is one of the most impressive bikes in the 125cc class. The bike caters to fast and slow riders alike. The power is easy to ride and an advantage for any rider who may be considered too heavy for the usual 125. Fortunately, Yamaha’s quality record combined with the four stroke’s inherent durability makes the YZ250F a great choice for avid racers or weekend players who need a machine that can handle a year of abuse without too much labor to keep it fresh.