Cycle News - Archive Issues - 1980's

There is one thing to watch out for with water- ooled dirt bikes - they may do their job too well. KTM technical services manager Mike Rosso warns of a possible fate - be careful of cold seizures in temperatures under 40 degrees, ancl be sure to give the bike su[[icient time to warm to operating temperature before motoring away. In the case of the KTM, Rosso recommends approximately one to two-thirds of the total radiator cooling surface be blocked 0[£ when the bike is ridden in sub-40 degree temperatures. Orange-colored chromemolybdenum steel frames have become a KTM trademark over the years, and with the removable rear frame section - an idea first used in modern times by KTM and copied by other manufacturers - we could find no fault in the finished product. ProLever (Progressive Leverage) is the name given to the single-shock rear suspension that lives behind that frame section. A nice feature of the shock linkage is grease fittings, allowing for imple preventative maintenance in this critical area. The latest version of the Dutchmade White Power shock is fastened into the heart of the system. The most visible change from last year's model is the addition of an integral nitrogen reservoir, eliminating several ounces with the lack of an external oil line and the accompanying mounting hardware. In addition to implifying shock removal, you will also find the rebuilding proces easier, since external re ervoirs complicate the La k. Also new are the compression and rebound adjusters. You can now adju t them by hand, and they have numbered click tops for quick reference. The compression damping knob is 10 ated atop the reservoir and easily reached, with a similar knob at the base of the hock body to alter the rebound qualities. The swingarm has undergone a major r vamping. It begins life as an aluminum extrusion, then is welded together and heat treated for maximum strength. The location of the Pro-Lever pivot points on the arm are slightly different, resulting in a revised leverage curve for better overall suspension performance. The spring ra te has a Iso increased sligh tl y. The system yields a full 330mm of travel, slightly less than 13 inches. Front suspension is provided by MarlOcchi, in the PA 40 SL version, with 40mm tubes. The uppermost portion of the tubes are knurled for a better grip in the triple clamps, prom pted by com pia ints (rom owners of the '83 model concerning excessive fork flex. Open class machines in the KTM line get the White Power inverted fork. Disc brakes are also becoming more or less a standard on MX machinery, but KTM decided to stick with doubleJeacling-shoe units - front and rear. The front is activated by a plasticlined cable, while the full-floating rear stopper is rod-activated. Nearly all of the plastic components have been reshaped for '84, from the gas tank to the rear fender. KTM has abandoned the practice of molding the ide number plates into the rear fender - the accepted European practice - and reverted to a pair of separate side panel to handle the numberhanging chores. As you can see, KTM pretty much followed the book with the 250 MX. But how well does it work? From our experience, very well indeed. Afterfilling the tank with therecommended 40: I mixture of gas and twostroke oil, the bike ea ily came to life 'after one or two kick - - quite suprising considering the extremely short length of the kick tarter. Onceon the track, the fir t thing we noticed was -. -. GET UPON THE TANK withthewinnerschoice: World Leader in One Piece Molded MX Replacement Seats Made of aircraft-quality urethane. ready to install on your stock seet pen. $ 39 95,~:=::::=, Cal. Res. add 6% Sales Tax I H'-':.,:-'TE / ------ colors available for all models. Call for other available colors. 402Q West Chandler Avenue Santa Ana, California 92704 (714) 979-4810 A DIVISION OF OLEA INTERNA TIONAL .b _~ ... "Manufacturers or Quality A"craN and Motorcycle Seats" Ask your dealer or call direct (714) 979-4810 DEALER INQUIRIES INVITED 39

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