Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/127586
eNEW BIKES e 1994 Yamaha YZs Yamaha focused most of its attention on the YZI25, which they say is to be significantly faster than the '93 model. 125 highlight of new YZ lineup By Chris Jonnum hat do new motorcycle releases and department store Christmas d eco rations have in common? Every year they seem to come a little sooner. H ere we are barely h alfway through 1993, and th e manufacturers are alrea d y sh owing off their new '94 m odels . Whil e th ere ha ve been gli mpses of prototyp e machines over the past couple of months, Yamaha is the firs t manufactu rer to bite the bullet and actually release details to the press on next yea r's motocrossers . While Jeff Emig an d his factory YZI25 won the '92 125cc National MX Championship and a re doing quite well so far in '93, the stock machine has earned a well -deserved rep uta tion for being slow. Yamaha apparently decided enough was enough, and focused the bulk of thei r attention on the 125, which highlights the '94 YZ lineup. While it doesn't appear drastically different from the '93 model, the '94 YZI25F is all-new from the ground up . Unfortunately, all the changes didn't come free, as the 125's manufacturer's suggested retail price received a $300 increase, to $3999. Improving throttle response and boosting bottom-end and midrange power were the top priori ties on the 125. Highlighting the changes to the powerplant is a new guillotine-type power-valve design, robbed from the tech n ol og y of the YZR road racer. Several of the other manufacurers also utilize this system. The new power valve - which also uses a revised governor - meant Yamaha had to build a new se t of cases, so they took advantage of the opportunity to alte r the inta ke tract, giving the fuel/air mixture a straighter an d more direct path to the new reed cage. Yamaha also gave the YZ a new W 26 cylinder an d p iston, red ucin g the stroke in an effort to achiev e quicker revvin g; it n o w fe atu re s a n a lmost square 54 x 54.6 bore and stroke. Steel clutch p lates replace th e a lu m inum pl a tes of last ye ar, and th e cl utch . springs now ha ve more preload. The clutch lever features a d ifferent bend, as well. Oth er changes to th e engi ne in cl u de a crank with a n in creas ed mome nt of inertia and an ignition with a longer spark duration . The silencer was shortened significantly, as well. In ad dition to the all-new engine, Yama ha gave th e YZ125 a brand-new frame for '94 . Hoping for a quickerhandling package, Yamaha pulled in the head pip e angle haifa degree to 24.7 degrees. The frame features different gusse ting, the swingarm uses a stronger (but lighter) aluminum alloy, and the top fork crown gets a ligh tweight one-piece des ign, all in an attempt to increase rigidity. The fork crown, which holds a handlebar with a flatter bend, uses a simplified locking mec hanism and does away with the ins ert that extended into the stem on the '93 model. In the suspension department, Yamaha actually decreased the suspension travel stroke on both the fork and the shock by lOmm. The fork now has 11.8 inches of travel, while the shock boasts 12.4 inches . Also, the diameter of the shock's compress ion valve was increased by four millimeters to 18mm, and the fork received new valving and stiffer spring rates. Continuing the manufacturers ' never-ending sea rch for the perfect brake rotor, Yamaha has replaced the cooling slots in the front and rear discs with cooling holes. Even the lightening holes on the front disk were changed, with a stiffer trian gular shape rep lacing the pa sse squarish shape of the holes on last year's now-obsolete rotor. The rea r caliper is slightly different, and the head of the rear brake pedal's mounting bolt is now flush with the pedal, providing a smoother surface for th e rider's boot. With the exception of a 10mm taller seat and stronger radiator shroud mounting points, last year's bodywork was retained, but the frame was painted purple like those of the factory team. New, yellow graphics appear similar to those on the NO team bikes. Surprisingly, the claimed dry weight of the YZI25 is 208 pounds. That's an . increase of 15 pounds over the claimed dry weight of last year's YZI25! The YZ250F fared much better under the scrutiny of the press last year, a n d perhaps because of tha t recieved far fewer u pd a tes than its smaller sibling. Unfortunately, it got an even bigger price increase than the 125, and at $4899, is a full $450 more expensive th an last year's model. On the ot her hand, its claimed d ry weight _ is only six pounds more than last year's YZ250. Th e 250 re ta ins last year's fra me, thoug h it receives more gussetting around the headset area. Unlike the 125, the 250 uses the sa me s teering head angle of last year's bike, though the ste ering lock now allows the forks an ad ditiona l three degrees of clearance. The 250 got the sa me suspension ! changes as the 125, along with the onepiece upper fork cla mp, new bra ke rotors, different swingarm material, flatte r bars, reshaped clutch lev er, smoother rear brake lever, taller sea t, p u r ple fr ame, ye llow g rap h ics and stronger shroud mounts. The YZ250 didn't switch to the guillotine-type power valve featured on the 125, tho ugh the old drum-type valve Despite few changes, the '94 YZ250 receives a big pric e increase, as does the YZI25. The Hoff -road" YZ250WRnow features an IS-inch rear wheel and a slimmer gas tank.