Tis the season to ride, the 2003 bikes are already here. In a continuing trend, manufacturers keep preempting themselves and we were forced at gunpoint to dirty our gear nearly a month early compared to a year ago. The latest incumbent to grace our idle hands is the '03 Yamaha YZ125. This little filly caused a ruckus by narrowly winning the infamous Dirt Rider 125cc two-stroke shootout in '02. Yamaha said, "so what," and was not about to rest on its laurels without upping the ante with its 2003 ride. Goggles in hand, we set out to determine what all of the hoopla was about. Here's the skinny.
When a machine such as the '02 YZ125 is already a fire-breather, the very notion of change starts us shaking in our boots. The old saying comes into play: If it ain't broke, don't fix it. Luckily for the men in blue, they tweaked a few things that needed a little twist and deducted some to give the bike a little weight reduction. We are not talking about anything drastic like a tummy tuck or liposuction, just a little leaning out. To highlight the changes, Yamaha now runs a thinner material through the backbone of the frame as well as new, lighter (but stronger) steel at the stamped two-piece sections of the frame. The swingarm end pieces are a little lighter and slimmer, and the suspension has been updated with new valving specs and lighter aluminum adjusters. The engine's cylinder received refinements to the exhaust port as well as to the cylinder head volume and combustion chamber. First and second gears are a little lower, while the carb, intake manifold, reed material and power-valve stop have all been fine-tuned.
A nice addition to the '03 YZ125 is the optional heavier flywheel weight. The added mass works when a rider likes a smoother pull or when a track is slick or muddy.
Read enough jibber jabber? Then we're off to the track. We will get you first off with the engine. Bottom-end is slightly improved from the '02. You can feel the extra bottom-end on tight 180-degree corners and in soft, loamy berms. For some of the heavier/faster testers, one tooth up on the rear sprocket was needed. The best attribute of the motor is its midrange power. You can shift a little early on the Yamaha and it doesn't fall off the pipe. There is more of a comfort zone now and you have to make a huge mistake to warrant some serious clutch abuse or the need for a lower gear. Top-end is pleasantly better than the '02 model. On fast, long straights, the YZ125 revs out further than most of the '02 125s we had ridden (except for KTM). This year the jetting is more precise thanks to a new spray bar in the carburetor, giving the YZ125 a little more overrev. Overall, the motor has a better snap off the bottom and is faster on top-end, while keeping its wide powerband and usable power intact.
With confidence to burn, the '03 YZ125 boasts the ability to charge fast sections without worries the bike will toss the handlebar around like a fish out of water.
Suspension has always been a good trait for the Yamaha YZ125. This year is no exception. The fork soaks up small chop really well and rarely gives the notion it wants to shake its head, even when charging through long, rough straights. The only downfall on the fork is that it is on the soft side. There is a little feedback because of its softness upon slap-down landings. Stiffer springs are a must for aggressive or heavier riders. We went in on the compression four clicks to firm up the ride. On the bright side, the rougher the track the better the fork shines.
The shock is equally impressive. We ran the sag at 102mm for both tracks we tested on. The shock handles square-edge straights without swapping or deflecting. However, it did seem to have a small problem when encountering rough and choppy ruts. The shock didn't want to squat down in the rear coming out of corners. We turned out the low-speed compression to soften the rear but it only hindered the bike's ability to land off jumps without bottoming. Again, heavier or aggressive riders will wish for a firmer spring out back.
Ergos are really comfortable even for taller riders. You can get up on the tank easily thanks to the flat seat surface. The on-the-fly clutch adjuster is a welcome touch. Good Excel rims are laced up on the blue tiddler and Yamaha even offers the consumer a heavier flywheel for different track conditions. The new brakes are as powerful, if not slightly better when compared to '02 YZs.
With all this in mind, the YZ125 is a great package once again for 2003. Is it the best 125? Only time will tell, and shootout time is coming!
The '03 likes to turn on a dime but we found the shock does like to hop when encountering choppy, rutted turns. We improved the feel by backing out the compression but that sacrificed bottoming resistance.
What's hot!
•Improved pull down low
•More top-end power
•Better gear spacing
•Great ergonomics
•Very stable at speed
•Suspension offers an improved feel over '02
Opinions
The '02 YZ125 was a very fast and stable machine, but the '03 is even better. The power is a little broader--if you can believe that. As soon as you get on the new Yamaha, you can feel the extra boost in bottom-end power. Top-end is slightly improved and the chassis is very stable at high speeds. The YZ is very predictable and does not do anything to surprise the rider. I would, however, like a 50-tooth rear sprocket for most tracks. The suspension was OK for fast, choppy tracks without any big hits, but if you have anything bigger than a tabletop jump at your local track, then you might want to consider heavier springs for both ends. The 2003 YZ125 is a great bike with little improvements that make it an even better bike than last year's, and that won the 125 shootout. But it is no 250F, though, is it?
--Kris Keefer/5'11"/165 lb/Pro
Much like the YZ250, this year's YZ125 has remarkable throttle response and very crisp power. Yamaha's '03 125 displays all the characteristics of last year's DR shootout winner with bigger bottom-end power and further revving ability. After riding the new YZ, I could not believe the boys in blue had managed to squeeze even more power out of last year's very impressive engine. Being right at the weight limit for a competitive 125 pilot makes me very sensitive to motor performance. The new YZ had no problems pulling me around the track, giving me plenty of boost to clear all the jumps. With the bike's light weight and nimble feel, getting into any line on the course was no problem. Front to back the suspension was very balanced but had a slightly harsh midstroke. With better power and the same plush qualities as last year's the new YZ125 has a great shot at repeating its shootout results.
--Jason Webb/5'10"/175 lb/Intermediate