Cycle News - Archive Issues - 1980's

. . • ••••••• ' '••• . . .* ' (Above) Water-cooled motor is potent and the power comes on fast. (Rig ht top) Corners can be taken power-on. (Ri ghtand be low right) The bike has a lean look to it. but the expansion chamber is fat. equal contempt. the 10.3 inches of travel soaking the harshness of the tra ck as well as any suspenders we've tested. On the mi nus side, however, is th e tenden cy for the fork legs to flex and so metimes be imprecise. More su bstantial tri pl e clamps might so lve th e problem . Suzuki's Full Floater rear suspen si on is superla tive. T he co nfi de nce th e ri sin g ra te suspension gives th e rider is impressive. Wi th I I in ches o f . tra vel, it doesn 't lead th e n um bers game, bu t co m p lia nce over stu tte r bumps and mons ter wh oo ps certain ly gives it the edge in tractability. Interest in gl y, we fo u n d the testers' riding styles and weight differences required much adj ust me nt an d n o on e sett ing in pre-load or dampin g seem ed to pl ease even simi la r riders. Lap times d idn 't change much with th e adjus tme nts, an d eac h tester felt th e Z model worked better th an th e '8 1 Su zuki even th ough we p icked it as best for th at year. Wat er-cool in g has been added to this year's middle-motocross bike, a n d th e effect is more th an j us t marketing st ra tegy . Power is up co nsi derabl y from la st year's R M, a nd it comes in rush es. In previous yea rs, Su zuki ha s taken ste ps to ass u re broad-range pow er for th eir 25Occ, but th is year horsepow er co mes on lik e th e aft erburner o n an F-15. T he a bru p tness o f th e power wa s a ca use of concern for nearly a ll th e rid ers. O n slippery corners, care had to be taken to prevent excessive wheelsp in or h aving the bike pitch sid ewa ys. In deep berrn ed turns, the front en d claws at the sky if th e rider grabs too much throttle. Care must be tak en to keep th e wei g ht forward wh en gra bbin g a handfu l. Experts loved th e motor, h owever. "Fastest 250cc ever" was o ne comment; a nd " P u lls lik e an Open class bi ke," a n oth er. Starting line drag races agains t other machines con. Iir m ed !'u r sea t-o f-th e-pa n ts op in io n of the R M's form id able engine. The Suzu ki bested every other 250cc that ran agai nst it and most of the assorted Open class machines. O n the track the story was the same. Competitors cou ld be passed on straights, even short stra ights, beca use the RM la unches itself lik e a cheeta h . Brak es a re important on a bi ke ca pa ble of suc h spee d. a nd fort u nat ely the Suzu ki' s a re u p to th e tas k. T he front brake remains a single leadin g shoe with good p rogressive feel, a nd th e rear brake ra rel y lock s a t in opportune moments. J ap an ese Du nl o p tires do an adequate job of tra ns ferr in g all th e br ak in g , co rnering an d acce lera tio n forces to th e tra ck . The Japan ese tir e co m panies have im proved th eir products co ns ide ra bly in recent years, and th e R M co u ldn' t wo rk as well as it does with out being shod with decent tir es. Suzu ki seems to ha ve designed th e Z fo r ri ders of short sta ture. The p egs a re h igh in rela tio n to the sea t a n d th e bar s low . T aller rid ers fel t so mew ha t cra m ped by the ergo nomics, but shorte r ride rs (especiall y o nes u sed to I25cc) made com ments lik e, " It's perfect!" It's hard to find a n noyi n g items on th e bik e, but the radiator scoo ps bo th ered everyone. When sliding up ont o th e ta nk for tight corneri ng, th e in side of a rid er 's lea thers ca tch on th e back edge of the shield . A handfu l of zip ties cu red the problem , but Suzu ki's oversi gh t in designing indica tes th at there is a lway s room fo r improvem ent. Mikuni 's new fla t-sided rect angular slide ca rb is a grea t im provem ent over the '81 ca rbure tio n. Power wa s crisp a t any throttl e setting, even when the motor was belo w th e u sea ble power ra n ge th e car b still jetted clea n ly. More ex perien ced riders wo uld use the cl u tch whe n_ex iti ng tig ht turns. bu t Novice riders were j ustrolljng on the th ro ttl e a nd pow- ering away withciu tt he hesita tion of last year's RM . Cleaning th e ai r filters rema in s a n a n noying hassle. A free brea th in g air cleaner is critica l to performance, a n d th e Su zuki en gineers sho uld en co urage th e effort by red esigni n g th e entire un it a n d dispo sin g o f th e num erous wa sher s. screws, bolts , spacers and n ut s used to secure th e two -p iece filt er desi gn. . T he choice of wh ich mot orcycle to b uy ge ts to be a tough er de cision eac h year. Manufacturers co ntin u e to improve th eir products, a nd every bike o n th e track is ca pa ble of win n in g, alt h o ugh some are more ca pable. It is a p p ro p ria te th at Suzuki runs a motocross school; the R M 250Z belongs a t • th e head o f th e class. Specifications Type liquid-cooled. two-stroke vertical single. " 246.3cc. D isplacement Bore and stroke _ 70mm x 64mm. Compression Ratio B.4: 1. Starting system Primary k ick. Ignition system Capacitor discharge ignition. Transmission Constant mesh five speed. Carburetor 38mm Mikuni. rectangular slide. Coolant capacity 1.0 liters (1.06 qts.). Frame design Tubular chromoly steel, double cradle. Rake/trail 29.3 degrees/4.88 in . Front suspension /travel ; Telescopic fork/1 0.3 in. Rear suspension /travel Full Floater/11 .0 in . Front t ire 300 x 21 Dunlop 4PR . Rear tire 5 .10 x 18 Dunlop 4PR. Dimensions Wheelbase 57.5 in. Seat height 38 in . 14 in. M inimum ground clearance Net weight 217Ibs. Fuel tank capecity 2 .2 gal. Suggested retail price $2099. 17

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