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/126751
Impr~88ion: J 984 Hontla CH250 Ana"-new redrochet By David Edwards If there is one thing you can say about Honda it's that they learn from their mistakes. Case in point: the Honda CR motocrossers. Remember the first silverand-green-tanked Elsinores back in 1973? In their time they were a revelation. Light, fast 10 and reliable, those early CRs, along with the Suzuki TM models, helped put Japan on the motocross map LO stay. But then came a five-year, laurelresting 'period that saw only token improvements made to the CR line. Slightly moved-up shocks and an engine spray-painted red seemed LO be Honda's only concessions LO progress during those years. In the [astpaced moLOcross world it wasn't enough and sales began LO drop, along with the frequency of Hondas appearing in winner's circles at amateur races around the country. Things got so bad that by the end of the decade there were only a couple of reasons to race a Honda: I) Someone was paying you to do so, or 2) your [ather owned a Honda shop and you didn't want to offend him. The situation began to cha'nge in 1981 when, aided by Roger DeCoster's developmental guidance, Honda came out with the Pro-Link-equippedCRs. In keeping with the modernization plan, the 125 and 250 were watercooled. During the next twO years Honda continued lO modify the bikes, and in 1983 the CR125, CR250 and CR480 were almost unanimous .choices as best in class by the motorcycle press. The 1983 CR250 was particularly impressive. One magazine claimed it was "the best dirt bike of 1983." And wrapping up their justification in 'naming it as the best 250cc molOcrosser of the year, the magazine said, "There is nothing that we'd change." With praise like that ringing in their ears, it would have been easy [or the motocross folks at Honda LO pack up their drafting pencils [or a year and wait [or the rest of the industry LO catch up. But they didn't; which brings us to the 1984 CR250. A quick glance at Honda's ·new quarter-liter racer doesn't reveal any earth-shauering changes, except for the addition of a di c brake up [ronl. Everything else looks the same as last year's machine; same red-orange plastic, same blue sa[ety seat, same clean, unified styLing. Closer perusal, however, uncovers the [act that Honda's engineers have changed almost everything. Heading up the list of changes is the 246cc powerplanl. It's still reedvalve inducted and water-cooled, but that's about all it has in common with its predecessor. The most obvious change is the inclusion o[ the ATAC system. For those whose mOLO-jargon is a liule behind the times, ATAC stands for Au toma tic Torq ue Am pi ification Chamber. In simple terms, the 250's ATAC system consists o[ a 170cc chamber allached LO the exhaust plumbing that is open at low- and mid-range rpm, but is closed of[ by a centrifugally operated buuer£ly valve at high I' (above 5800) rpm. When the chamber is open. the duration of the exhaust's reflected pressure wave is extended, in eHect "tricking" the engine into making more low- and mid-range power. The ATAC hardware allowed the CR's engine designers to tune for more LOp-end power -theexpansion chamber and· intake, transfer and exhaust ports were all altered with more power in mind - without worrying that they were creating a high-strung, hard-tohold-onto monstrosity. Owners of '81, '82, and '83 CR250s will notice that Honda has revised the engine's internals so that the kickstarter is now on the right side and the countershaft sprocket is on the left. This allows [or sligh tly easier starting since the rider can now start the engine [rom the saddle, rather than having LO go through the more cumbersome procedure o[ dismounting and kicking [rom a standing position. More importantly, £lipflopping the chain drive to the left side means that the rear sprocket and rear brake drum are now mounted on opposite sides o[ the hub, instead o[ the all-on-the-right set-up previously used. The switch allows a slightly narrower and lighter rear hub assem· bly and permits the rear brake cable to be tucked inLO the space previously occupied by the chain, where it is less susceptible LO damage. Other engine changes include the useof a specially hollowed-out crank· shaft weight that is an impressive 13.4 'ounces lighter than last year's weight, a beefed-up shifting mechanism and aluminum, rather than steel, clutch plates. With the engine changes, Honda claims their new red rocket pumps out 43 horsepower at 8000 rpm, a three-horsepower increase (:lVer last year's bike. As you might suspect, the frame andsuspension weren'tleftouto[the upgrading. The 250's steering head has been moved back and down slightly and the rake has been pulled in lO a relatively steep 26.7 degrees,