Cycle News - Archive Issues - 1980's

~ z W ..J U t; a: o b ~ > '" a: w > w '" ~ ~ o u o z <{ t: o ..J o U ~ ~ ..., Ii w ~ The FZ750 cockpit. (Below) Rear shock preload and rebound damping is adjustable by remote controls under right side cover. ..J :. The Yamaha FZ750 is an incredibly-strong runner at the dragstrip; our !::: best pa.. was 11.20 seconds at 120,00 mph under not-ideal conditions. ~ r-"....,1Il '" 5 x ... An FZ750 camshaft (top) and plain-bearing crankshaft. To keep engine width down. crank flywheels double as primary gear and ignition triggers. Test: Yamaha FZ750! By John Ulrich , The amazing thing about the Yamaha FZ750 is. that it performs like an 1100. We're not talking here about a hand-built prototype flown into the U.S. for a 10-lap press intra at Willow Springs Raceway. What we 've got here is an honest, production-line FZ ridden on the street, on the racetrack and 22 " and at th e dragstrip. I had a GSllOO a couple o f yea rs ago, a nd ra n it in O pen Stock Production ra ces in California. It was a stro ng 1100, with pl enty of acce leratio n a nd good top speed. I took it to th e drags once to see what it wo u ld do, and turned IU8 on a pe rfect da y at th e now-defunct Orange County International Racewa y. . Since th en I've been a t Carlsbad Raceway o n a p oor day with thin a ir a n d lousy tracti on a nd watched g uys from a m oto rcycle magazin e swea t a n d strai n a nd work and no t ge t a n ew GS I 150 to run any quicker than th at o ld GSIIOO o f m in e. Wh ich br i n g s us to th e FZ750 Yama ha test bike, whi ch, after 1000 q ,!i.c~ :,! ~~ -ha r~. ~treel m.il~~, !<,>,!~d , . ...... ... . e . . .. • o·. itself at Carlsbad on May 2, with nary a look at th e spark plugs or an oil cha n ge or a n yth ing els e. It was a decent da y, not the best, not th e worst, a nd tra ction wa s a problem , as it o ften is at Carlsbad. And it took seven passes for that a mazin g FZ750 to stop th e li gh ts at 11.20 seco nds, 120.00 mp h in the standing-start quart er mile. T he bik e didn 't waste any time ge tting down there. ei the r; th e first pass was 11.549 @ 119.20; th e seco nd run was scra tched wh en th e rear tire lit o ff up o rr th e line; th e th ird was 11.44 @ 11 9.68. A co u p le o f sets o f three pa sses each with two o ther bikes bei ng tested a t th e dr ags (a 700 Max im a nd a 500 Int erceptor) a nd the re wa s a lmost eno ug h ru bber la id dow n on the slippery track to make h ard la unches possi ble. T he£ourth run was 11.44@ 118.89, followed by 11 .37 @ 119.36, 11.28 @ 119.84 and then th a t 11 .20 @ 120.00. o n d esert ed h ighwa y straightaways without th e ride r tuc ki ng in , and doesn 't tak e very long to ge t up th ere , eit he r. It 's geared low, sp in n ing a ca lcu lated 4600 rpm at 60, a nd indicating 5000 rpm on th e tach a t a n indicated 72 mph. But a tank's worth of accel era ti ng ha rd around to wn an d cruisin g a t 5000 rpm on th e freeway still found th e Yamaha returning 53 miles per ga llon. Which may be wh y Jimmy Filice says the FZ750 he raced a t Daytona got abo u t 30 mph in th e 200-mil e ra ce while being run as hard as he co u ld make it go. T he worst m ileage we go t out of th e FZ750 was just dipping int o the 40s. At anything close to legal speeds (read, 70 mph), even with hard acceleration where appl icable, the FZ would typically go 240 miles before we had to select reserve by pushing a rocker switch mounted on the left sid e of the frame-mounted fairing. There's a fu el gauge, (a lo ng with a tach, speedometer and coola nt temperature gauge), and it's accurate. Our FZ750 sp u ttered a nd demanded reserve j ust as the needle hit th e red zone, making it th e first realisti c fuel gaugc;/."e've seen on a street bike. Ma ybe more a ma zi ng th an the m il eage is th e broad p ow erband. H ere' s a n engi ne th at's redlined at 11,000 rpm a nd yet it pulls very stro ngly from 5000 rpm , ki cks in hard at about 6500 rpm a nd ha s respectable pulling p ow er down at 3000 a nd 4000 rpm , too . The engine pulls well wh en sh ort-sh ifted aro u nd to wn (w hic h doesn ' t lea ve m uch time betwee n shi fts :...- th e tra nsm ission has six close ly-spaced ratios) and sp ins up to the redline ver y qui ckly - it has a light cran ksha ft. It does n 't sto p revving a t 11,000; our test bike saw It was h ard wo rk ge tti ng the FZ down th e track th at quickl y; th e bike ma de enough power th at it dem anded bi g burnouts to h eat up th e rear tire an d th en still wanted to light up orr the lin e - th e hard part was feel in g th e precise clutch en ga ge me nt po int a nd feeding in the clutch quickl y enough to get a hard launch without ge tt ing too much clutch , too soon , a n d ei the r lighting up th e tire or doin g a wh eeli e, both being excelle nt method s of wa sting tim e th at would be better spe n t accelera ting. The Yam aha 's clutch doesn 't have a precise feel ; th e h ydraul ic system doesn't give th e rider good feedbac k and m ak es th e engagem ent paint seem narrow an d vague. That's why Sam McDonald's Yamaha-backed FZ750 Superbike has been co n verted to a ca ble clutch actua ting system . It was the clutch that turned out to be the limiting factor on that day at Carlsbad, with this rider. Five more passes d idn 't improve th e time. a n d th ere wer e four tire-spinning aborts mixed among them. The five passes were 11.67 @ 119.04; 11.22 @ 119 .~ , 11.24 @ 120.48 , IU7 @ 120.16 and I U 5 @ 120.48. The m ethod that worked best on th e dragstrip in cluded launching a t 7500 and feeding in full clutch a t full th rottle a s soon a nd as fast as the rear tire would tak e it . At lea st th at wa s th e goal , while tr ying to deal with the clutch engagem entpoint limi tati on s. Full-throttle pow er sh ifts at th e 11,000 rpm redline had th e FZ750 running through th e lights a t close to redline in fifth gea r. It wasn ' t much of a su rp rise th at the FZ750 was fast at th e drags. It' s fa st o n the street, too. lun gin g forward like a n 1100 whe n th e thrott le is wh acked on in top gear fro m 5000 rpm . It'll p~ ll an i n?icat~d 130 mph ~ ; I · ' ~ i :; ,. ~·. i, l fl" '" 'l'" r - )11 ' ( , )" ilt- F:i '. ] l" /) i ~

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