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/125863
Sto ry & photos by John Ulrich The engIne grabs your at tention right off. People don't expect to see all those cylinders and pipes bristling out o f a 250. The po werplant is an underbored v.ersion of the 5 3 (an d also , the now-defunct 52 350) , Kawasaki's 400cc triple. The bottom end is identical, with the 5 I B sporting smaller cy linder and head castings, and a smaller bore . A larger rear sprocke t on the 5 I B helps the 250's narrower powerband pull the same basic running gear (m in us the 53's front disc brake) . Impressed with both the tradition of fast Kawasaki triples and also the SIB owner's manual (which has a special section on fast riding considerations and which mentions race preparation several times), we took our test bike out for some very hard running on a fast and twisty road. This 250 is pretty swift off the line if you start with the ta chometer needle abo ve 7,000 RPM, but it isn't a rocket ship like its 500 and 750cc brothers. Shifting into second at the 8, 500 RPM red line brought the engine off its strongest range of powerband. The gap is almost too much for the 250 to handle comfortably. You have to push it well into the red zo ne to overcome the gear gap when trying to go fast as possible and shifting at 9,000 RPM helped. The powerband is somewhat narrow. pulling strongly from 7 ,ODD RP~I up to Specifications Engine Type Three cyl inder pis ton po rt ai r cooled two stro ke Bo re X St ro ke 1.77 X 2 .0 6 in . (45 X 52.3mm) Displacement _. _ 249cc (1 5 .2 cu . in. ) Compression rat io _.. _ _ 7.5 : 1 Carburetion .. _ (3) 22mm Mikun i Recomme nded fuel _. . . . . . . . . . . . . . . . .. . _ Regular battery-coil, three sets of po ints, t hree co ils Ignition Starti ng Kick it Shift pattern ' _ _ _ Left foot , u p for up, 1·N -2-3-4-5 Other stuff Dry w e ight (cla imed ) _ _ . . 339 1bs. Whee lbase _ _ __ _ 53 .7 in . Height 43 in. 32.3 Width G round clearance _ __ .. _ 6 in. Gas mileage du ring test _ 30-35 MPG Suggested retail price, West Coast _ __ 5970.00 24 about 9,000 RPM. Below that there just isn't muc h. and not enough ponies to move the bike under 4,000 RPM. The speedometer reaches the clai med maximum top speed (90 MPH) only with t he rider tucked in and the engine run 500 RPM past the redlinc to 9,000 RPM. The fro nt brake has adeq uate power , but requires an awful lot of p ress ure at the hand lever. The rear brake is m uch the same, except t hat it fa des more and faster than the front brake does. The front brake is pretty good in spite of the pressure required, but not as good as the discs the competition is using. Riding any dis c-equipped b ike after a ride on the 5 I B, a rider will be immediately impressed with the power and light pull of the disc. relative to the Kawasaki's front drum . After 15 hard miles , the engine felt fine, but the rear brake was scalding hot and useless. The front brake was also ho t, but still worked. Riding at about 25 MPH a rider could pull in the clutch, stand on the rear brake, and still coast for a good 30 feet before noticing any significant slowing from brake action. The rear brake's stopping capabilities cam e back after a 45·minute cooling session . When we were riding it , we had to keep m oving our braking po in ts back. Running the machine as hard as possible for a total of 49 miles. it delivered slightly less than 30 miles per gallon . In normal use it got about 35 miles per gallon. Ran ge before hittin g t he .4 ga llon reserve was about 115 miles. The bi ke b urned o ne quart of two-stro ke o il in 750 m iles. T he co ld engine w as usu all y eas y to st art w ith th e non -prim ary kick starte r if the proper drill was follow ed hand lebar mounted cho ke full o n , throttle clo sed. T he bike ran best (an d fas test) im m edia tely aft er t he engine reached th e p oi nt o f bein g just warm eno ugh to run without th e cho ke on . Soon after , the p ow er d ropped a lit tle to a po int wh ere it w ould rem ain no matt er how lon g we ran it. T h e e n g i ne w ould idle very con ten ted ly at stop lights, turnin g a little ove r 1,000 RPM. It n ever fo ule d a plug during o ur testing an d never had an y m alfunctions. The b ike will cru ise up to 70 MPH (at 7,000 RPM ) o n the freeway, carrying a passen ger , with no pr oblem. So metimes it w ill ta ke full throttle to keep it at cru ising speed w hen faced with larg e hill s or headwinds, and sometimes it w ill lose five or ten MPH under those co ndi tio ns. S ide win ds and ra in grooves a ffec t th e bike more than man y larger, heavier machin es, bu t it d oes n ot do 'an yt hing unco ntrollable in eithe r situation . On a sixty mil e ride o ne day, our ace lad y frien d and passenge r co mfort te ster co mp lained about excessive vibrat ion in the passenger foot pe gs and also th e sea t pad d ing an d sha pe. Even th e pilot will be gin t o squirm on th e sea t after 20 miles o r so. Vib ration is no t an im po rtan t problem in t he handlebars or t he fron t pegs. T he fact th at th e passen ger pegs also serve t o bolt o n th e m ufflers adds to th eir vib ration tendencies. T he shocks an d forks give a very stiff ride. There is one ro ugh section of freeway we like to use as a shock test. This Kawasaki, (with units that prompted onc Kawasaki official to proudly point out that one of the first things to be changed with the impending production of Kawasak is in Am erica are the rear shocks in favo r o f "ones th at wor k " ), m ad e th e t ester sorry he had ever t ak en t hat free way. Every exp ansio n joint and settled slab boundary w as transmi tted through t o th e rider's guts. Changin g sp ring pre-load did n o t help, b ut maybe a kidney belt would have .. . La ck o f ad eq ua te shoc k abso rp t io n was th e o nly thin g t ha t kept th e 5 1B fr om be i ng a fine, co mfortable mo to rcycle to ride on th e streets and freewa ys on sho rt co m m ut ing tr ips bac k an d fo rt h. On high , sweepi ng tr ansit ion roads between freeways, the 51B did not bobble or wob ble as long as the rid er d id not m ake any sudde n mo ves and stayed smooth . , The tool kit contained a bunc h of tools, but none of them fit the rear ax lc nut of our test hike. The tool kit lived in the racy-Iook ing compartment behind the seat, secured by this year's improved seat lock. There was room in the compartment 'for a road map , a pair of