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/126902
(From left to right) The Suzuki's motor isn't much better than last year's, despite the new power valve. The Yamaha's motor is slightly tamer, while the Kawasaki's has better snap off the bottom. A new power valve design (HPP) on the Honda gives it a stronger and wider powerband. works-like responsibilities, but the works will be worth it." Along with the new power valve comes new porting specs, a narrower piston port intake reed-valve chamber, and a lighter Nikasil-plated cylinder liner; enabling a tighter piston-tocylinder clearance, a higher compression ratio and better heat dissipation. The oval-bore, 38mm Keihin carburetor is 2.0mm larger than the carb used last year. The exhaust pipe is redesigned as well, with a new aluminum silencer attached. The five-speed transmission is beefed up and has slightly different ratios; the kicks tarter has a new gear ratio, too, for easier starting. The wet clutch has a redesigned lifter cam for a lighter pull on the clutch lever. The CR now comes with 43mm Showa forks, which are similar to the ones used on last y.ear's works bikes. They are the cartridge-type forks, which are also found on the CR500. The cartridge surrounds the rebound damper unit, keeping it free from air bubbles that form when the fork is hard at work. This keeps the damping action smooth and consistent. The fork has heavier fork springs and still have external rebound and compression damping adjustments, but the compression damping now has 14 settings instead of 12. The rear Pro-Link suspension isn't radically changed but is refined to make the shock curve more progressive by lengthening the bottom link 17mm. Plus, internal valving has been modified to match the different linkage ratio.. Rear wheel travel is slightly (2mm) shorter. Most of the other changes made to the Honda are minor. The frame has the same dimensions as before, but is built of tubes with slightly thicker walls, and the single down lUbe from the steering head is now square, instead of round. The swingarm pivot bracket is more rigid, and two more bearings (for a total of four) have been added to the pivot area. The rear wheel now has two roller bearings (instead of one) on the drive side, and the rear sprocket has two more teeth (53). Seat height i 3mm lower and handlebar width is 10mm narrower. Kawasaki KX250·D2 Last year's Kawasaki played second fiddle to the Yamaha, and although the 1986 KX doesn't look much different, It does have numerou refinements. The onl y noticeable change is the addition of a 7.5-inch rear disc brake, which the other three bikes don't have. Other than that, most of the changes are internal. Much effort went to improve the Kawasaki's low·end, and overall engine performance. The cylinder head was milled to increase compression; intake ports were enlarged; the KIPS (Kawasaki Integrated Power-valve System) has larger ub ports, valve openings, and a redesigned governor. and the exhaust pipe is reshaped, primarily for tronger mid-range. The eight-petal epoxy-resin reed-valves 16 is still fully adjustable, with external high- and low-speed compression damping settings. The gas tank and seat are moved forward ISmm, and the seat is ISmm narrower at its widest point; the han· dlebars are also mounted farther for· ward, and the ribbed fenders are 10mm wider. Footpegs are also 10mm wider. Yamaha YZ260G Even though last year's YZ was the best Japanese 250cc motocrosser o~ the market, Yamaha felt the YZ stil needed major changes for 1986. That', evident when eyeing the all-ne" Monocross rear suspension and radi cal styling. The new Monocross real suspension, which utilizes a Yamaha, built shock, is (like the Suzuki) rede signed to lower and centralize weight The bottom of the shock runs throug~ the swingarm, where it attaches t( new linkages; the shock is mounte< lower and farther foward in the fram9 as seen on works Yamahas three year: ago. The shock uses a piggy bad reservoir as well as the BASS (Brake Actuated Suspension System) useo last year. The BASS system decrease: compression damping when the real .brake is used. The new Kayaba forks have heav ier springs, more rebound damping and the sliders are treated with Alum ite anodizing to reduce friction be· tween the stanchion tubes and slid ers. The Alumite also decreases alu inurn erosion from the sliders, redu ing contamination and deterioratio of oil. Fork boots are no longer used Suzuki RM250G Yamaha YZ250S Engine type .....• Uquid-cooled. reed-velve. two-stroke single Bore x stroke 68.0x68.0mm Displacement 246cc Compression ratio 8.2 to 9.7:1 Carburetor . . . . . .. 38mm Mikuni Horsepower ..... 46 bhp @ 8250 rpm Torque ..... 30.2 ft/lbs. @7500 rpm Starting system Primery kick Ignition COl Lubrication . . . . . . . . . . . .. Premix Primary drive Streight-cut geers Finel drive #520 chein Gear ratios Primery 63/24: 2.625:1 Final 50/14; 3.571:1 6th 22/23; 0.956:1 4th 24/21;1.142:1 3rd •.••...... 26/19; 1.368:1 2nd •......•. 28/16; 1.750:1 1st 30/14; 2.142:1 Frame Single downtube, split double credle used last year have been replaced by .. carbon-fiber reeds to improve throttle response. Other engine changes include exhaust ports which are no longer bridged, and a more-advanced ignition curve. The 40mm Mikuni carburetor is the same, but there is' new jetting to match the KIPS changes. The five· speed transmission is slightly beefed up; third and fourth gears now have sq uare dogs for better engagement, and the outer clutch hub is 2mm wider (46mm). The most radical change in suspension was made to the 43mm Kayaba forks. Kawasaki's Travel Control Valve (TCV) system has been adopted, varying fork compression damping according to travel. In theory, the TCV allows the fork action to be extremely sensitive over the smaller bumps, while maintaining enough compression damping to absorb the rough stuff. The fork has 16 externally adjustable compression damping settings, as before. The Uni-Trak rear suspension isn't much different from last year's design. Unlike the 1986 KX125, the JtX250 (and KX500) continue to use the Uni-Trak strut design, but with improvements. The shock strut adjustment bolt has been enlarged 2.0mm to prevent breakage, a common problem for many 1985 KX owners. The shock body is now 6.0mm larger (46mm), and shock rod diameter is up 2.0mm, from 14 to 16mm. The Kayaba shock Reke Tl1IiI Front suspension type 28.0° 4.69 in. Telescopic fork Fork tube diameter 43mm Front wheel trevel 12.0 in. Rear suspension type Single shock swingerm Reer wheel trevel 12.6 in. Front brekes 8.9-in. disc Reer brakes 5.12-in. drum Front wheel 1.60x21 in. Reer wheel ....•.... 2.15x18 in. Fronttire ... 80/100-21 BS M22 Reertire .. 100/loo-18BSM23 Claimed dry weight. . . .. 21 3 Ibs. Certified wet weight 236.5 Ibs. Overall length 86.4 in. Dverell width 33.5 in. Overall height 48.4 in. Wheelbase 67.9 in. Fuel capecity 2.1 gel. Ground cleerence 13.4 in. Seat height 37.6 in. Colors White Reteil price ........•....• $2699 Engine type ..... Uquid-cooled, reed-valve. two-stroke single Bore x stroke 67.0x70.Omm Displacement 246cc Compression ratio 8.3:1 Cerburetor . . . . .. 36mm Mikuni Horsepo_r N/A Torque N/A Starting system Primary kick Ignition Suzuki PEl Lubrication. . . . . . . . . . .. Premix Primery drive .•.... Streight-cut geers Finel drive ..•...... #620 chain Geer ratios Primery 59/23; 2.565:1 Finel 50/14; 3.571:1 6th 22/22; 1.000:1 4th 21/18; 1.167:1 3rd 25/18;1.389:1 2nd 27/16; 1.688:1 1st 29/14; 2.071:1 Freme Single downtube, .plit double credle Reke 28°60' Trail .........•...•..... 4.4 in. Front suspension type .... Telescopic fork Fork tube diameter 43mm Front wheel trevel 1 1.8 in. Rear suspension type Single shock swingarm Rear wheel trevel 12.4 in. Front brekes ....••....... Disc Reer brakes Drum Front wheel 1.60x21 in. Reer wheel 2.50x18 in. Front tire .. 90/100-21 Dunlop Rear tire .. 110/100-18 Dunlop Cleimed dry weight .•. 2131bs. Certified wet weight 235 Ibs. Dvel1llllength ..•...... 86.0 in. Overall width , 33.7 in. Dverell height 49.8 in. Wheelbese 57.5 in. Fuel cepecity 2.1 gal. Ground cleerence 14.0 in. Seat height ..•.•.•.•.. 36.6 in. Colors .••••..••..•..•.. Yellow Retail price $2649