Cycle News - Archive Issues - 1980's

~ Riding imllression: 1990 Kawasaki KX125 eGreen revo ution By Nate Ra uba Photos by Kinney Jones an d rebound damping adjustments. co m p letes th e U n i-T ra k design. There are a lso new wider footpegs, a n d th e bolt-on a lu m in u m rear su bfra me asse m b ly is interchangea bl e with the KX250. The tank, radiator shrouds, swingarrn / shoc k assem b ly a n d front forks is a lso interchangeabl e with th e KX250. Tucked withi n th e new p erimeter fram e. th e I24cc engine also go t some arteru ion and sees se vera l refinem ents. Bore and stroke rem ains th e same a t 56x50.6, but th e single-r ing pi ston h as been redesi gn ed a nd is now co ncave. Redesigned exha ust and scaven gin g ports, plus a n im p ro ved ' Ka wa sa ki Integ rat ed Power -va lve System (KIPS ) exh a us t va lv e i s u tilized to ex tract mo re horsepower. There is a new , low -boy exha us t pipe to keep the weig ht down low a n d ce nt ra li zed a nd a new ovalsection silencer is des igne d to reduce noi se, The 35m m cresce nt-slide Keih in carburetor fea tures a "Je t Block" in th e botto m of th e venturi to get tu rb u lent-free ai r th ro ugh th e ca rb for better transition of p ower. Air reach es th e ca rbu re tor through a .... ~ .D 6 (l) > o Z The all-new KX 1 2 5 features the f irst perimeter frame t o be found on a pro duct io n motocro sser. a wa sa ki has kept everyone anxiously awaiting the arrival of the all -new, perimeterframed KX 125. Its release may be a littl e lat e co m pared to th e other brands. and Kawasa kis of years past, but a n a ll-new ma chine sometimes holds up production and delays its arrival. Ka wa sa ki tota lly redesigned th e KXI 25 fro m the grou nd up , a nd is the first to ut il ize a perimeter fram e o n a productio n mot ocross mach in e. Bu t th e frame isn' t the on ly new item o n th e KX 125. T here 's a lso a new set of inv erted fo rks, new top-en d for the engi ne, a nd of course a who le new look for th e Kawasak i, including wi ld new graphics. T he n ew fleet of Kaw asak is ar e j ust beg inn ing to trickl e in to America, a nd th ere are so few th at we co u ld o n ly get o u r hands o n o ne o f th e bran d-new mach in es for a few days o f riding. The new components Ka wa sa k i h ~ s been usi ng t he perimeter fra me design on its street bikes for severa l years now, but this is th e first time that o ne has shown up on a produ ction motocross ma chine. The box-section fram e is made of h igh -ten sile steel a nd the perimeter design forms a st raigher path from th e steeri ng head to the swingann p ivo t, ma king the frame more rig id. The perimeter fram e design also made it possib le to posi tion th e 2.2ga llo n fue l tank lower to bri ng down th e overall cen ter of g ravit y. Instead of drap in g over a frame backbone, the KX 125 ta n k drops down to th e cen ter of th e bi ke. It also ma kes mai nte na nce a littl e b it easier since the ta nk hangs int o th e center of the mac h ine in stead o f over th e side. There is easy access to th e carbureto r for jetting ch an ges, an d the top end K 16 o f the m o tor can be pulled off withou t rem ovin g the tank. Las t year th e KX 125 was th e widest bike arou n d, but th is time the sea t and ta nk hav e been made slimmer, a lt ho ug h the b i ke is s ti ll w id e enough to get a good grip o n wit h yo ur knees. T here are also new radiator shrouds, side co vers a nd rear fender to go a long wit h th e tank cha nge . In creased frame rigidi ty is needed to handle th e grea ter loads p laced on th e frame by th e new, upside-do wn Ka yab a cartridge for ks. Ka wasaki wa ited a year to fit th e KX lineu p wit h the 4 1mm in verted forks si nce they felt th at th eir design needed more testin g to perfect. T here a re 16 rebou nd a nd co m pression da m pi ng adj ust rneru s so th at th e forks ca n be fin e-t uned to just abo u t any track and/or rid ing style. In vert ed for ks h elp m ake a ny machin e turn quicker since there is less for k fl e x , b u t the KX I25' s turn ing is furth er imp rov ed b y decreasi ng th e steering angle by one degree. At th e rear, th ere is a slig h t cha nge in th e U n i-T rak suspe ns io n linkage ra tio a nd linkage assembl y gro u nd cleara nce has been in cr ea sed b y 15mm wi th th e addition o f a br acket. T he ex tr uded a lu m in u m swingarm h a s b een s tre ng t he ned w i th a n a ddi tio na l cross pipe fitt ed just beh ind th e sw i nga r m p ivo t. A Ka yab a shock, with 16 co m p ressio n All of the bodywork. the f ront forks and rear subframe is interchangeable with the KX250. Dual rad iators repl ace the old left-side single cooler. The seat and gas tank are easily removed to reveal the new frame , redesigned airbox that br eathes from a ll four sides. In add itio n to the top open ing a nd th e closeable shutters on th e sides o f th e a irbo x, th e bottom is a lso designed to both drain any wa ter o r mud that ge ts in th e airbox an d allow a ir to co me in . There is a lso a lar ger a ir filter elem ent. Spa rk is provided by a digitallyco nt ro lled C Ol unit an d an add itional ge ne rator coi l has been added to im p rove ho t spark character istics. The engine is cooled by all-n ew . dua l para lle l-flo w radiators . which boo sts cooling capacity over th e ol d single-s ided ra diator Kaw asaki has used since liquid-cool in g the K X l25 severa l years ago. T here were n o signi fica nt cha nges m ad e to th e transmission , a lthough a floating-t ype cl utc h. li ke th e o ne used o n last yea r's KX500, has been ad ded to improve engage me n t feeling. How does it work? So , ho w much o f a d ifferen ce in handling does th e a ll-new, incredibly rigid frame mak e? Except for prolevel or very-fast intermediate race rs that can ride the KXI 25 at th e very

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