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/126801
an 00 0') ..... Test: 1985 KTM 250MX ~ifiRii ~ii Aiiii~aa i@ ~ilg By Kit Palmer .i.,ait • Forget any talk that all European motocrossers are too heavy, too slow and too under-suspended to successfully compete against Japanese motocrossers - it j ust isn't true anymore. Maybe past European machinery couldn't handle the onslaught of lightweight, hi-tech MX bikes from Japan. But now that single-rearshocks and water-cooling are old news - and since no new mind-blowing innovations have surfaced in moto· cross - some smaller European factories have reached the same technological plateau that Japanese factories have been stuck on for the past two or three years. The small, Austrian factory is reaching for that plateau with its '85, inverted-fork-equipped, 212-pound KTM 250MX. Although the new 250 looks very . . I' almost all·new. The motor is still water·cooled with two radiators, a reed·valve two-stroke with a new 5mm-longe{ stroke. The longer stroke is designed to give the engine quicker and cleaner throttle response. The cylinder has a Nika!oil COaling- and the piston is forg-ed. . For better durabilit\,. tilt' left (Tank bearing .was relocated. Last year's KTMs had the bearing lubricated by transmission oil, and it was discovered that after a long period of time, the bearing would wear out because ohhe tiny metal fragments that accumulate in the oil from the wearing of transmission parts. Now the bearing is lubricated from the clean gas/oil mixture. remain the same at 67.5 x 69mm and ~t~~c; the engine produces 4H and is found on the left side of the engine. It is very thin and short, and is mounted high in the case. A primary kick system is used. Supplying a NGK BIOES spark plug with spark is a Motoplat external-rotor ignition. Guarding the magneto from damage is a p~stic cover held on by three hex-head bolts. Suspension and chassis received the majority of changes for '85; most obvious is the new inverted fork. Built by White Power, the fork is called the 4050; meaning 40mm stanchion tubes, and 50mm sliders. Last year; the KTM 500 was the only model to come with the inverted fork; this year KTM's complete line-up is so equipped. The fork on last year's KTM 500 needed more attention, so revised damping and fork springs are found in '85. The complete fork system is much lighter than last year's conventional Marzocchi forks, 2.0 pounds to be exact. Protecting the vulnerable stanchion tubes are tough plastic strips with one end mounted io the slider. In the rear, the Pro-Lever suspension system went through many refinements: The linkages have a straighter and less progressive lever· age ratio, and the White Power shock . is carried 20mm lower in the frame. The shock has a piggyback reservoir, with eight external compression damping adjustments and 12 external rebound damping adjustments. Rear wheel travel is I! inches. Zerk fittings have been added to all suspension pivot and bearing points. The single-downtube, split-cradle frame has a new detachable rear subsection, very similar to the Honda. CRs. The complete frame is painted red and has 0.50 less rake at 26.5 degrees; trait is four inches. Wheelbase remains the same at 58.8 inches, while ground dear;mce is up to 1!.8 inches. Seat height is a tall !7.4 inches. The kickstand is mounted to the swingarm on the left side and has been redesigned for better stability when the bike is moving. It can be easil y removed if desired. Up front, there is a 9.4-inch floating disc brake wtih a dual-piston caliper braided-steel line. The floating disc is not rigidly mounted to its carrier, but rather can float slightly side· to-side. So when the disc gets hot, there is less chance of warping. The rear brake is not a disc; it is a drum with a double-leading-shoe design. The brake pedal is stronger [or '85 and is attached to a steel rod that connects to the rear brake linkages. Both the rear brake assembly and rear sprocket are located on the same side of the hub. Both aluminum alloy rims are laced :~~ ~~:;~~.~~~;~~h:iMet~ :~~;;~~~~h~~:.:r~nda4.60-18Per- th~~~~:~'\~r~~~~~~:~~~~~~ K':~::'7hhl~~~i~n~r~~re~:e~s~~ winds its way up and across the left side of the bike. At the end of the pipe isanew, aluminum oval silencer that is fully rebuildable. Supplying the combustion chamber with the correct air and ga-s mixture is a !8mm Bing carburetor. It has a pull·type choke knob located on the right side ofthe carb body and comes stock with a #190 main jet, #280 needle jet, 8L2 jet needle, #50 pilbtjet and 215 slide. Within the magnesium cases is a fi ve·speed transmission and a wet, multi·plate clutch. The transmission vent is now much larger. Also new is the oil drain plug location: It is positioned for easier access and is better protected from rock damage. The folding shift lever is made out of steel. stronger and the side number plates are larger. Both side panels are mounted to the frame by snaps; no tools are needed for removal. The radiator shTouds are redesigned and are attached to the plastic gas tank and radiator by four screws. The gas tank is now larger, because the right' side of the tank extends lower - it holds 2.4 gallons. The air box is now one piece. Handlebars are slightly shorter this . year at 32 inches. The grips have a' waffle· type pattern and the levers and throttle housing are made by Magura. Inside the blue vinyl seat cover is softer foam. The complete package weighs 212pounds dry, making it the lightest 250cc motocrosser to date, narrowly edging the '85 CR250 Honda by less to last ear's 2.50iiiithiie.'.85.iiis.iIIIiBoiiriie.a.niild.siitriioiikiieiaiiniididilii·siPliilaiiciieliim.eiin.t •••.•• • Tihii~iiikiiiiciiik.suiiiiiriiteiir.leiivieiriils.stl.per • •tiiiiin.y• •iithiiia.n.ojjjn.e.po.u.njjjd . • • • • • • • • • .J