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/126839
The GPz1 OOORX has the GPz900R's balancer shaft with a f ull-cradle frame and rubber front engine mounts and rig id rear engine mounts. It feels heavier than the 900 at slower speeds, largely thanks to very wide t ires, yet steers quicker at higher speeds. The extra power shows up in mid-range and topend, and one magazine reportedly stopped a GPz1000RX at 158 mph on radar; quarter -mile t imes are mid-to-high-1 O-second-bracket. GPzJ.OOORXfech Externally simi liar to the w ell-proven GPz900R Ninja engine, the new lOOORX powerplant has been subjected to a number of modifications designed to both improve th e performance, a nd help it hang together under th e increased workload. Both bore and stroke have 18 been in creased 10 br ing th e ca pacity up to 997cc; wh ere th e 900 Ninj a m ea sured 72.5 x 55m m for its 908cc, th e 1000's d im ensions are 74 x 58mm. T h e co nrods a re thicker an d ar e m ad e from stro n ger steel to handle th e 9% pow er boost; th ey're also heavy . Bigen d bolts are up l.O mrn to 9.0mm, a nd th e wrist pins have been beefed up while losing wei ght over th e 900 ver sions. Kaw asaki quot es an in crease in ' pi ston speed from 63.16 10 66.61 feet per seco nd a t th e 10.500 rpm redline, a lthough max imum power co mes in 1000 rpm ea rlier; on th e ra ce tra ck. th e bike actua lly pulls harder if shifted u p at 9000-9500 rpm . The same o ld rev Iirniter cu ts th e sparks a t j ust over 11 ,000 rpm . New lightwei ght va lves. b igg er 36m rn sem i-flat-s lide car bs a nd new in take valve tim in g (o pe n 40° BTDC, close 70° ABDC aga ins t th e 900' s 45° a rid 65°) a rc th e m ajor changes 10 th e cvlinder head a n d valv e train, a lthough Kaw asaki claims th e new a ir bo x, with its . In takes just behind the steering head . is respo ns ibl e for a good percent ag e of th e power inc rease . It ram s den se, cool a ir down the ca rbs, and co m bi ned with a 10° in crea se in ca rb downdraft angle (no w 15°). th is mak es th e 1000's throttl e response from mi dran ge up a bsolu tely flaw less. New flat-topped pistons acco u nt for an extra 1.3 bhp whi le dropping th e co m p ression rat io from 11.1: I to 10.2:1. The upper co m pression rings have been red esigned with barrel faces a nd a bevell ed inner edge. Th ese twi st a little a s th e piston tra vels up a nd down 10 wed ge tightly betw een th e top and bottom o f th eir groo ves for better sealing a nd wear. Valv e lift rem ai ns a t 9m m, a n d even the valv e sizes stay th e sa me a t 29mm intak e, 24.7 ex ha us t. The in cl uded valv e angle is identical to the 900 Ninj a' s a nd it seems Kaw asak i didn't find a ll th at much room for improvem ent in the nearl y-two-yearo ld engine , beca use th e maj ority o f the spec ificat io n rem ains unch an ged . It 's the sma ll tou ch es, th e refin in g of detail, th at accou n t for th e rem a inder of th e spec. Exhaust h eaders are now mad e from sta in less steel, a nd th eir diam eter's up from 35 to 38. 1mm with out an y weight increas e becau se of si ngle-wa ll co n struc tio n used rig h t throu gh the system . Owners in hot cl ima tes often co m p la ine d of overhea ting with th eir Kawasaki GPz1 OOORX fngi ne type . . . . . Water-cooled, DOHC . inline-four Bore x stroke . . . • . • • 74x58m m D isplacement .. . . . . ..•• 997cc Compression ratio : 10. 2 : 1 Carbu retion (4) 36 mm Keihin CV Hor sepow er . . • . • • . . 123 bhp @ 9500 rp m Tor q ue • . 73 lb .-ft. @ 8500 rpm Valves per cylinder . ...... . • • 4 In ta k e valve size 29mm Exhaust va lve size 24.7mm Intake lift 9mm Exhaust lift •• • ... .. . .... 9mm Includ ed valve angle . • . .. 34.9° Int ak e va lve t iming • • •• • 40-70° Exhaust valve t iming •• • 65-45 ° (m easu ring pt.] . . ..• ....• Omm Starting system . .. •.. .. Electric Battery rating •..• . . 12V 14AH Ignition . • • • • • • • • Transistorized electronic Lub rication Wet sump Red line . . . . . • .. • . . 1 0. 5 0 0 rpm Rpm @ 60 m ph • . .. .. 3800 rpm Primary drive . • • . . . Straight-cut gear Fina l drive . .. • . . . . O-ring chain Gear ratio s 97 /56; 1 .732:1 Primary Fina l 40/15 ; 2.666:1 29 /2B; 1 .035:1 6th 5th •• . . .. . • . 30 /26; 1 .153: 1 4th 32 /24; 1 .333:1 3 rd ... . . . • . • 35 /22; 1 .590:1 2 nd ; 38 /19; 2 .000: 1 1st . ... . • . ... 42 /15; 2 .800: 1 Calculated speed in gears at red line 6th 166 mph 5th 149 mph 4th 1 2 9 mph 3 rd • . . . . •• . . . • . . .• . 108 mph 2 nd •• • • : • ••. • • •• •. . . 86 mph 1st ... . •. • ... .. .. . ••. 61 mph Fra m e . . . . . . Double -downtube. rectang ular·steel t ubing; bo lt-on alumin um rear section Rake 28 ° Trail ••••. . . . • .•. . . . .. .• 4 .3 in. Front suspen sion type •.• . Tele scopic forks Fork tube diameter 40mm Front wheel travel 5.3 in . Single Rear suspension type shock swingarm Rear wheel travel . •. • . . . 5 .1 in . Front brakes •• • •. . .. (2 ) 1 1-ln. hydraulic discs Rear brakes .. • • • •. • • . 10.2·in. hydraulic disc Front wheel . . • . . • . 2 .50x16 in . Rear wheel • •. . .. • • 3.50x16 in. Front tire .. ..•. . • . 120/80-16 Dunlop F17 Rear t ire • • • • • . • • • • 150/80-16 Dunlop K725 Claimed dry weight . .. . 525 lb . Claimed wet weight • .•• 582 lb. Overall length . . • •.. .. . 87.8 in. Overall width .. ...... . • 28.5 in . Overall height 47.8 in . Wheelbase . • • ••• • • • • • . 59.3 in . Fue l capacit y 5.5 gal. 5.5 in . Ground clearance Seat height 31 .6 in . Co lo rs Red /black. black /grey. blue /silver Retail Price N.A.