“Maxxis Tires” – Basic Metal #182 “1985 Kawasaki KX250” – PulpMX

For this version of Basic Metal, we’re going to look again at Kawasaki’s all-new “Works Reproduction” KX250 for 1985. 

All-new for 1985, Kawasaki’s redesigned KX250 was filled with improvements and magnificence. Photograph Credit score: Kawasaki 

The early 80s have been a troublesome time to be using inexperienced within the large bike courses. Whereas Kawasaki had lastly cracked the code for fulfillment within the small-bore divisions, that they had continued to wrestle with the bigger machines. On this period, the KX250 and KX500 have been exceptional extra for his or her oddball styling and problematic reliability than their efficiency on the monitor. Cracked frames, damaged hubs, leaking exhausts, and brittle plastic have been all a part of the KX possession expertise throughout this time. On the KX60, KX80, and KX125, these reliability bugaboos have been offset by class-leading efficiency, however within the 250 and 500 class, Kawasaki’s motocrossers struggled to garner a lot affection. 

A redesigned airbox for 1985 used a snorkel routed alongside the body spine to attract cool air into the motor. Dubbed the Recent Air Consumption System (FAIS) this new design was added to all of the full-sized KX fashions. Photograph Credit score: Kawasaki  

Within the 250 division, the KX was little greater than an afterthought in 1984. The machine provided up-to-date know-how with liquid cooling, a robust entrance disc binder, and their Uni-Trak single shock suspension, however its efficiency turned out to be lower than the sum of its components. The KX’s motor provided a robust low-to-mid surge that rocketed the machine out of corners, however its transmission was notchy, and its clutch was almost hopeless. The lengthy and tall chassis made turning a chore, and the suspension bottomed, banged, and bucked its method across the monitor. Its outsized ergonomics match tall pilots properly, however until you had the inseam of Paul Bunyan, there have been higher 250 decisions out there in 1984.

All-new bodywork for 1985 slimmed the KX’s pilot’s compartment, elevated rider safety, and did away with a lot of the earlier mannequin’s quirky look. Photograph Credit score: Moto Revue 

Whereas Kawasaki’s 250 had did not garner a lot success in 1984, its smaller brothers had captured shootout victories in all their respective divisions. The KX60, KX80, and KX125 swept their competitors with right-sized chassis, succesful dealing with, and rompin’ stompin’ motors. For 1985, Kawasaki appeared to convey a few of that small-bore success to the 250 class by fully redesigning their deuce-and-a-half platform. All the things from the chassis, to the bodywork, to the motor, was all-new, with an emphasis on enhancing dealing with, smoothing ergonomics, and boosting the usability of the KX’s powerband. 

The enduring advert for the all-new 1985 KX fashions was so good that Kawasaki reused the identical picture once more in 1986. Photograph Credit score: Kawasaki 

At first look, essentially the most important change on the KX250 for 1985 was its radically redesigned bodywork. In 1984, the KX250 provided a fairly quirky visible bundle that was a mixture of outdated and new-school designs. The disc brake and radiator shrouds pegged it firmly within the Nineteen Eighties, however its rear fender-mounted quantity plates have been a vestige of FIM laws from the late Seventies. It was an odd mixture of outdated and new styling that riders tended to both love for its uniqueness or loath for its lack of class. 

For 1985, Kawasaki added an all-new “energy valve“ system to the KX250 to broaden efficiency. Coined the Kawasaki Built-in Energy-valve System (KIPS), this new design mixed parts of Yamaha YPVS and Honda’s ATAC into one design. By each altering the porting and including an exhaust resonance chamber, Kawasaki believed they may present the final word mixture of energy and management. Photograph Credit score: Kawasaki 

In 1985, the KX250 adopted the extra mainstream look launched on the KX125 in 1984. This meant sleeker strains, extra compact dimensions, and a retirement of the love-it-or-hate-it rear fender in use since 1982. Up entrance, the brand new fender was longer and wider for elevated mud safety and not employed the very “Euro” alloy fender brace seen in 1984. Within the rear, an all-new design deleted the built-in quantity plates and provided a decrease and longer profile that cleaned up the styling and lowered the probabilities of being whacked within the bottom within the tough. An all-new tank provided 2.1 gallons of capability and afforded a slimmer format to make sliding ahead in turns simpler. Repositioned radiators sat 2.12 inches decrease on the body and intruded much less into the pilot’s compartment. An all-new blue saddle featured a good-looking redesign of the KX brand and provided a 10mm decrease seating place to accommodate a wider cross-section of riders. The redesigned facet plates afforded elevated safety from the recent exhaust and lowered the quantity of roost flung on the rider from the rear wheel. The general format of the KX was a lot improved for riders beneath six ft in top with the machine adopting an ergonomic really feel extra in keeping with its Japanese rivals. Whereas the brand new format was properly obtained by most, long-time Kawasaki devoted may go for the optionally available taller seat and reverse the offset bar mounts in the event that they most well-liked the stretched-out really feel of the older inexperienced machines.

New radiators for 1985 have been longer and deeper for improved cooling and mounted two inches decrease on the chassis to slim the rider compartment and enhance dealing with. Photograph Credit score: Kawasaki   

Along with the redesigned bodywork, the ’85 KX250 featured an entire remodeling of the chassis to enhance dealing with and scale back weight. An all-new “high-tension metal” (HTS) body featured a discount in general measurement and extra aggressive geometry for an improved steering really feel. The wheelbase was lowered by almost an inch and extra gusseting was added in vital areas to assist forestall the cracking points Kawasaki’s frames had grow to be infamous for. An all-new Uni-Trak rear suspension system featured a redesigned linkage that allowed the trip top of the machine to be fine-tuned utilizing an adjustable rocker-arm strut. Whereas Kawasaki touted this new function, additionally they curiously suggested in opposition to utilizing it as a result of hazard of an improper adjustment inflicting a severe failure. If the strut was shortened to cut back the seat top, it may additionally trigger the rear suspension to backside harshly and trigger the strut to bend or break. If this was a reputable concern, it begs the query of why this function ever made it to the manufacturing machine. Maybe this concern was unanticipated till it was too far into manufacturing to make a change. Whatever the reasoning, Kawasaki made it clear in all their press briefings that it was finest to not mess with this adjuster if attainable. 

An all-new Kayaba shock for 1985 added excessive and low-speed compression changes and a brand new heat-compensating valve to fight fading. Photograph Credit score: Kawasaki  

On the suspension entrance the 1985 KX250 featured some of the superior shocks ever provided on a manufacturing machine. The all-new Kayaba damper broke new floor by providing separate changes for each excessive and low-speed compression damping. This was greater than a decade earlier than this type of multi-level adjustability would grow to be commonplace inside the business. The shock provided 12.6 inches of journey with 4 selectable settings for high-speed compression and twelve settings for low-speed management. Rebound damping may be adjusted with 4 settings out there. Along with its almost limitless adjustability, the brand new shock featured an revolutionary system to struggle fading by way of using an automated warmth compensator. As temperatures inside the shock elevated, a tapered needle valve was engaged to extend the damping power. With these improvements, the KX250 provided essentially the most superior rear suspension out there on a manufacturing machine in 1984. 

The 40mm VM40SS Mikuni carburetor employed on the KX250 grew 2mm in measurement for 1985 and added an revolutionary new “R-slide” to cut back consumption turbulence for improved throttle response. Photograph Credit score: Motocross Motion 

Up entrance, the 1985 KX250 was much more typical in its design. All-new 43mm Kayaba forks provided 11.8 inches of journey and eight out there changes for compression damping. Rebound management was not externally adjustable however there was a brand new three-way mechanical adjuster constructed into the highest of every fork that might be used to fine-tune spring pre-load. Internally, the forks remained a standard damper-rod design however new alloy internals lowered weight for 1985. Revised damping settings appeared to enhance the ’84 fork’s abysmal efficiency and a brand new alloy steering stem lowered weight. To minimize the possibility of snagging the forks in a rut, fork protrusion beneath the entrance axle was lowered for ’85 and the fork gators of 1984 have been deleted to permit extra cooling air to make it to the repositioned radiators. Each entrance and rear axles have been upgraded for 1985 with the entrance rising 2mm and the rear gaining 3mm in diameter. Braking continued to be dealt with by a entrance disc/rear drum mixture, with the rear gaining a better-sealing backing plate and the entrance adopting a 10mm bigger rotor for 1985. 

Trick exterior preload adjusters for the forks and reversible offset bar clamps helped make the KX some of the revolutionary machines in its class in 1985. Photograph Credit score: MOTOcross 

On the motor entrance, the KX250 was simply as all-new for 1985. In 1984, the KX250 provided a robust motor that hit laborious however signed off quick. It was fast from nook to nook however lacked the robust top-end pull of sophistication leaders just like the Honda CR250R. In 1985, Kawasaki appeared to broaden the KX’s energy profile by implementing their model of a “energy valve” for the primary time. Coined the Kawasaki Built-in Energy-valve System (KIPS), this new design integrated parts of each the variable port timing of the YPVS (Yamaha Energy Valve System) and the exhaust resonance chamber of the Honda ATAC (Automated Torque Amplification Chamber) into one design. By each various the exhaust port timing and altering the geometry of the exhaust system, Kawasaki’s engineers believed they may present the optimum mixture of energy and value. To accommodate the brand new KIPS mechanism, Kawasaki’s engineers needed to dial up an entire redesign of the KX’s motor. The cylinder, head, instances, and backside finish of the motor have been all reconfigured to work with the brand new variable exhaust system. The redesigned prime finish maintained the bore and stroke of the outdated design however featured all-new porting and repositioning of the primary exhaust port to the middle of the cylinder. Displacement remained at 249cc, and the motor retained the identical 9.1:1 compression ratio it had utilized in 1984. Redesigned coolant passages within the cylinder and head improved coolant circulation and helped forestall detonation beneath heavy masses. To assist deal with the ignition failures that plagued the KX the yr earlier than the lead wire terminal was strengthened and the crankshaft contacts have been enlarged to guarantee a strong connection. The CDI’s ignition curve was additionally remapped to optimize throttle response and supply a smoother supply of energy.

The 249cc KIPS mill within the KX250 was filled with energy in 1985. It was much less robust down low than the Honda and Yamaha however got here on like a ton of bricks within the midrange. Prime-end energy was a lot improved over the yr earlier than however screaming it was not the simplest method to make use of its potent powerband. Photograph Credit score: Brian Waingrow 

For 1985, Kawasaki added the power to regulate the KX’s trip top with an adjustable Uni-Trak strut. Photograph Credit score: MOTOcross 

 Feeding gasoline to the redesigned prime finish was an all-new carburetor and consumption system for 1985. An all-new airbox elevated quantity and an revolutionary new consumption system drew air immediately from behind the entrance quantity plate. Dubbed the Recent Air Consumption System (FAIS), the brand new design consisted of a snorkel that ran from behind the radiators alongside the primary body spine to the highest of the airbox. This allowed the KX to attract cooler and brisker air into the motor for improved efficiency. Along with the freer-breathing airbox, the brand new KX250 adopted a redesigned reed-valve and all-new consumption manifold for 1985. The brand new reed valve featured air guides in its design to cut back turbulence and eight works-style carbon-fiber reeds to offer lightning-quick throttle response. A brand new 40mm (2mm bigger than the 1984) Mikuni mixer fed gasoline to the redesigned engine and featured an revolutionary flat-bottomed “R-slide” that Kawasaki claimed supplied higher atomization of gasoline at low RPM. New radiators for 1985 have been longer and deeper for improved cooling but additionally narrower to offer a slimmer pilot’s compartment. The brand new exhaust tucked in higher on the tank and featured an all-new form designed to work with the KIPS. 

On Kerker’s dyno the KX250 pumped out a peak of 36.5 horsepower. This put it on the absolute prime of the 1985 250 class. Whereas its spectacular horsepower numbers pointed to its efficiency, most riders most well-liked the chunky low-mid energy of the Yamaha over the mid-range blast of the inexperienced machine. Photograph Credit score: Filth Rider 

On the underside finish, the KX featured all-new instances that integrated the ball-ramp governor and {hardware} wanted to energy the KIPS mechanism. An all-new clutch moved to a floating-type engagement for the hub and redesigned clutch arm for an improved really feel. The clutch-side case lacked a quick-change cowl, however there was a helpful sight window constructed into the design that allowed for fast oil inspections. The transmission remained a five-speed close-ratio design with all of the ratios unchanged from 1984. A brand new shifter featured aluminum development, a folding tip, and a revised form for a extra optimistic engagement. 

By far the largest flaws within the Kawasaki motor bundle for 1985 have been its recalcitrant clutch and cussed transmission. Regardless of an all-new hub design, the clutch continued to be grabby, tough to modulate, and averse to severe abuse. Photograph Credit score: Kawasaki 

 On the monitor, the all-new KIPS motor was totally different, however not essentially higher than the 1984. The brand new motor supplied much less torque than the yr earlier than, however a stronger midrange and longer pull on prime. This lack of grunt made the inexperienced machine trickier to get connected out of corners and fewer responsive than tractors just like the brawny Yamaha YZ250. As soon as on the pipe, the KX was aggressive with something within the class, and the bike’s new-found top-end pull made it extra interesting for quick guys who discovered the outdated motor considerably missing. At a peak of 36.5hp, the KX was the strongest 250 Filth Rider examined in 1985, outpowering the Yamaha by almost half a horsepower. 

Whereas the KX250 had loads of energy, its lack of low-end, hard-hit, and grabby clutch made easily exiting turns harder than on its opponents. Photograph Credit score: MOTOcross 

Whereas the KX provided loads of thrust, its clutch and transmission continued to be a significant hindrance to its efficiency. The redesigned clutch provided a light-weight pull nevertheless it continued to be a chirping, snatching, and grabbing mess. The machine’s lackluster low-end response demanded the rider use lots of clutch out of turns and this shortly exceeded its modest tolerance for abuse. The clutch’s on/off engagement and aversion to hammering made the bike’s energy considerably tougher to make use of and even highly-skilled riders discovered it tough to modulate the KX’s abrupt powerband successfully. Out of turns, the clutch bucked and lurched, and executing the subsequent shift usually required the rider to again off the throttle. On paper, the brand new motor was extremely aggressive, however its grabby clutch and recalcitrant transmission significantly hindered its effectiveness on the monitor. 

The 250 class was comprised of lots of flawed machines in 1985. Yamaha owned the motor of doom however was saddled by atrocious suspension. The Honda had the perfect detailing, a torquey motor, and unbelievable seems, nevertheless it lacked the horsepower to run on the entrance. The Suzuki owned the crown for the perfect rear suspension, however just like the Honda, its mellow motor wanted extra ponies to be aggressive. Within the Kawasaki camp, you had large energy, slim ergos, and a high-tech suspension, however its poor clutch and lack of grunt made it a tough machine for less-skilled riders to handle. Photograph Credit score: Motocross Motion 

On the dealing with entrance, the KX was improved however nonetheless a step behind the best-performing machines within the class. At 218 kilos on Filth Bike’s scale, the KX was three kilos lighter than the 1984 KX250 and the lightest of all of the Japanese 250 choices in 1985. This paid main dividends on the monitor the place the KX felt nimble within the air and simple to throw round. It was a succesful jumper and almost everybody commented on how a lot lighter the brand new machine felt in comparison with the yr earlier than. Turning precision was noticeably improved over earlier Kawasaki choices nevertheless it remained much less exact than shredders just like the Honda CR250R. Within the turns, the KX’s entrance finish by no means felt totally planted, and the machine tended to face up mid-corner until the rider was exact together with his method. On exit, the abrupt energy and difficult-to-modulate clutch made it difficult to get the KX connected and the machine tended to both spin the rear tire or seize traction all of the sudden and unload the entrance finish. At velocity, the KX was strong with not one of the headshake that might make the Honda a biblical-level expertise. The occasional kick from the rear shock may upset the chassis, however the Kawasaki by no means tried to tear your fingers off the bars or threaten to swat you want a fly if you happen to hit an surprising bump at velocity. Total, it was a solid-handling bundle that jumped properly and went straight with confidence however demanded extra talent and focus within the turns than its opponents.

Good forks and a terrific entrance brake highlighted the entrance finish of the KX250 in 1985. Photograph Credit score: Kawasaki 

With essentially the most superior suspension within the class, the KX250 had rather a lot going for it in 1985. The Uni-Trak was nearly infinitely adjustable with its variable linkage and three-way damping adjustability. For these versed in suspension idea, this opened a world of potentialities, nevertheless it additionally made it very simple to get misplaced within the suspension weeds. The KX’s many out there settings made it simple to get issues fairly incorrect, however if you happen to acquired it correctly dialed, the KX provided a really aggressive rear suspension bundle. Quick riders thought the inventory spring was a bit gentle and the rebound damping of the KYB shock might be a bit fast, however general, it did an excellent job of smoothing out the monitor. So long as you didn’t fiddle with the rear strut, bottoming was no problem and the KX’s rear suspension was ranked by many as the most effective out there in 1985.

The Uni-Trak rear suspension on the KX provided a ton of adjustability in 1985. Whereas quick guys wanted a stiffer spring, most riders discovered its efficiency greater than acceptable in inventory situation. Photograph Credit score: Kawasaki 

Up entrance, the KX’s KYB forks have been a lot much less of a black field of thriller and carried out very properly in most cases. As soon as once more, the inventory springs have been a bit gentle for quick guys and those self same riders complained the rebound was a bit too fast. With out an exterior adjustment for rebound damping, this was not simply addressed, however riders of extra modest expertise discovered the forks to be plush and well-sorted. The externally adjustable spring pre-load was taken proper off Jeff Ward’s works racer and afforded a degree of customizability not present in its opponents. With this adjustment and eight settings for compression damping, most riders have been capable of finding a setting that labored properly. Some riders did complain of stiction within the mid-stroke when the KX was new, however this appeared to minimize because the forks broke in. Whereas not good, the KX’s inventory forks have been good general performers and positively raceable in inventory situation for many riders beneath the professional class. 

The brand new adjustable strut turned out to be a significant failure level for the ’85 KX. Onerous landings may bend it on the adjustment level and quick riders have been properly suggested to observe it very fastidiously or exchange it altogether with an aftermarket unit just like the one featured above from DMC. Photograph Credit score: Motocross Motion 

On the detailing entrance, the KX was a little bit of a combined bag in 1985. Technically, it was essentially the most superior machine within the class with a works-level shock, dual-function energy valve, trick air consumption, and zoot capri forks. Its adjustable strut provided the power to fluctuate trip top, and its offset reversible bar clamps provided works-level customization. It was a motorbike for the eighties with all of the doodads and gizmos any self-respecting moto-head would need. Whereas this degree of know-how was welcomed by most, not each innovation proved a blessing. The multi-adjuster shock’s operate was not well-explained within the proprietor’s guide and plenty of discovered its multitude of settings inscrutable. The brand new adjustable strut additionally proved a significant level of failure with many riders experiencing bending on the adjustment level. Body breakages continued to be widespread, and the footpegs have been lower than severe abuse. Plastic and {hardware} high quality have been poor, with fenders that simply cracked and bolts that simply stripped. Inventory sprocket and chain high quality have been of the pot metallic selection, however this was par for the course for Japanese machines of the time. Total motor reliability was good, however the KIPS added important complexity to a top-end service, and the electrofusion coating Kawasaki used for the cylinder liner meant a seizure might be extraordinarily expensive. Vibration was additionally the heaviest of the Huge 4 with greater than a little bit of tingle making it by way of the KX’s bars.

Flat turns and slick dust performed main havoc with the KX’s turning manners. With a berm and a few traction, it was able to altering route, however its entrance finish by no means felt as planted and confidence inspiring as a lot of its rivals. Photograph Credit score: Motocross Motion 

Trick rubber covers protected the throttle, clutch, and entrance brake controls, and the inventory bar bend was appreciated by most. The brand new bodywork was slim and cozy with many riders cut up between the Honda and Kawasaki as having the perfect layouts of 1985. Brake motion entrance and rear have been robust and optimistic with the entrance disc ending behind solely the wonderful dual-piston Honda binder for energy. Whereas robust, various riders famous points with air contamination inside the Kawasaki’s hydraulic system. This shortly turned the KX’s entrance brake really feel to mush with the Kawasaki demanding extra frequent bleedings than its rivals. 

Trick, highly effective, and on the chopping fringe of design, the KX250 was a flawed however aggressive 250 alternative in 1985. Photograph Credit score: Kawasaki 

Total, the 1985 Kawasaki KX250 turned out to be a strong machine totally undone by an unruly clutch and notchy transmission. The brand new KIPS motor pumped out essentially the most energy within the class and its refined suspension provided works-level tunability. Its mediocre turning, gentle suspension, and lack of low-end made it a troublesome promote for Supercross, however its potent energy, slim strains, and plush suspension earned it lots of followers in 1985. Even with its grim clutch, cantankerous shifting, and spotty construct high quality, the KX was a well-liked alternative for a lot of. Quick, futuristic, and flawed, the 1985 KX250 was the quintessential mid-eighties motocross machine.