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/126836
.Kawasakis, KTMs ~ revealed at Ponca ~~ City l.!") .0 8 .... (l) 0. (l) CFJ By Kit Palmer PO NCA CI TY, O K. AU G 8 Suzuki , Kawasaki and KTM introduced their full line of 1986 production motocrossers at the Grand National Motocross Championships in Ponca City, Oklahoma. T he Suzuki R Ms a re the most . rad ica lly changed from 1985, espe cia lly th e a ll -ne w, larger in-size 1986 R M80. All of Sum- " . ki s 198? m o tocr~s sers h a ~e bn gh t b lu e-p a inted. revised engines, n ew su spensi on an d slim me r p ro files. Kawasaki 's m o st -chan g ed KX is the KXI25, w h ic h n o lo n ger ha s a strut o n the Uni-Tra k rea r suspensio n (the KX250 and KX500 still use a The 1986 RM250 Suzuki is slimmer, with a new Full-Floater rear suspension system and an engine that's painted blue (all the new RMs have blue engines). For better low end power, the 1986 RM250 has a smaller, 36mm flat-slide Mikuni carburetor and a power-valve. The engine is also longer; bore and stroke is now 67x70mm instead of 70x64mm. stru t). T he KX500 n ow has K.I. P .S. (Kawasa k i In teg ra ted P o wer -val ve System ), an d a ll have front an d rear di sc brakes. KTM 's line-up is h igh lighted by th e a ll -ne w 80MX th at was sup posed to m a ke i ts U .S . ra cing d ebut at Po nca City' th e bi kes arri ved in th e co u ntry too' la te to be prepped for th e race. Th e KT M 250MX h a s a n ew Digi tal Control ign ition system; th e 125MX, 250M X a nd 500MX KTMs h ave fro nt a nd rea r disc bra kes. Suzuki's RM 125 is now equipped with a power-valve similar to that on the 250, but the unit is mounted above the exhaust port, instead of below. As in the case of the 250, much emphasis went into making the bike narrower with oval frame tubing and a slimmer seat and gas tank. The exhaust pipe, which used to be routed outside the frame tube (behind the right side panel), now runs through it--similar to what the works bikes have. The RM80 is all new for '86 with more horsepower and a bigger frame . Seat height is now two inches taller. but the wheelbese rem ains the same at 48.6 inches. Rear suspension is similar to the 125 and 250 (travel has been increased by one inch at each end to 10.4 inches), and it also has a front disc brake . The RM80 also has a longer-stroke motor (47.5x46.8mm from 49x44mm) along with a larger M ikuni carburetor, 28mm, up from 26mm. 14 A knob on the power va lve alters the spring preload on the exhaust ' valve itself and adjusts the powerband by changing when the powervalve opens. Th e 1986 production R Ms have sma ll inspection windows over the power-valve mechanisms, just like the 1985 works bikes. Clutches on both the RM125 and RM250 are slightly changed: Overall engine w idth i s reduced this year, making room for a rack-and-pinion clutch-actuating system in st ead of the previously-used push rod . To increase rpm and peak horsepower, the impeller in the water pump on both the RM125 and RM250 is now lighter, with three blades instead of five.