During the last several years the Yamaha YZ125 has been the bike to beat. Yamaha has claimed several championships with the successful 125 and has taken the top spot in several shootouts. This year Yamaha took the same approach with the YZ125 that it has in the past: it simply fine-tuned an already dominant machine. The new YZ125 got a good going-over for 2004. The most notable changes were the 48mm fork and updated internals. The fork comes with an all-new hydraulic bottoming-out system. The motor received a few changes, basically updates to the cylinder and exhaust pipe. Yamaha also took a few extra steps in paying attention to detail--the YZ comes with titanium footpegs and a gripper seat cover.The Yamaha YZ125 has always garnered great reviews in the handling department, and this year was no exception. The Yamaha turns and handles perfectly. The new 48mm fork works well and gives the bike more response in turns. The fork is a bit more rigid than last year's, but the feedback it gives inspires confidence. The chassis seemed well balanced; Yamaha recommends running the sag at 100mm. In order to get the bike to turn better in tighter corners we tried running the sag at around 95mm, which works well on tight, slow tracks, but overall 100mm of sag works best. Turning the YZ was easy and tight, and on long, fast, sweeping corners the bike hooks up. The stock suspension settings worked well for nearly all of our test riders with just a few clicks on the compression to stiffen up the fork. The new hydraulic bottom-out system works well. Over- or underjumping big jumps never really upset the bike, and gone is the harsh metal-to-metal feel. The brakes on the YZ are solid and consistent. The ergonomics felt good and are comfortable for just about any size rider.When it comes to power to the rear wheel the YZ125 takes the cake. Off the bottom the motor is a bit on the dead side. Test riders felt themselves using a lot of clutch to keep the revs high out of turns, but hey, it's a 125. Midrange is where the YZ125 comes on strong, and on this bike midrange power is responsive and usable and pulls into good solid top-end with a decent amount of overrev. In an effort to get more pull out of turns we opted to run a 49-tooth sprocket rather than the stock 48-tooth sprocket. The one-tooth change made a big difference throughout the powerband. Getting out of tight corners was easier, the throttle response was better and a tad less clutch was needed. Also, to get a bit more response, we played around with the air screw on the carburetor; a few test riders went from one and one-third turns to two turns out. Playing with the air screw seemed to get rid of any little misses or hiccups the motor had.Without a doubt, the '04 YZ125 is one of the best bikes out there. A bit of fine tuning went a long way. The new fork makes a huge difference and was liked by everyone. With all the new four-strokes out this year the competition is stacked in the motor department. Other than a lack of bottom-end the motor runs strong and builds confidence, especially when taking on big jumps for the first time. The new titanium footpegs are wide and work well. Yamaha's quick-adjust clutch lever works flawlessly. Our only real complaint with the blue lagoon is that it has looked the same for too long. The bike needs a graphic change or color change--something to make it seem like a new bike. It's a small complaint, but it would be nice to see a change in looks.