Cycle News - Archive Issues - 1980's

>.... ro ;:j .... ..0 Q,) The V -M ax represen t s a f resh . o riginal approach to motorcycle styling. M o st ride rs w ill see only the t aillig ht. ~ The V -fo ur engine is actuall y compact : it s sleek profile was hi dden by t he fa i ring lowers of the touring Venture . front o f and above th e carburetors, with chrome highl igh ting the int ake mani folds, cylind er head fins a nd exhaust p ipes. Lo ok at th e V-Max from th e side a nd it has th e V-look of power, Yama ha 's styl ists say. They call it " power-flo w" styling. Th e rear end o f the V-Max is ca lcula ted to look thi ck a nd so lid like the huge rear ends on dragsters; a t th e same ti me , th e front end is kept as simple and clean as po ssible to loo k lik e the sp ind ly front ends fou nd on drag ma chi nes. T here' s just on e instrument on the ha ndlebars, a ch ro me d speedome ter , and the tin y tach is located in a sm all pol ished-a lu m in u m cluster in front of th e false gas ta nk, wh ich co vers the a ir clean er and air box . Th e real ga s tank is located undernea th the seat , a head of the rear wheel, and is rea ched by removi ng the step ped front sectio n o f the seat. Th e V-Max is a hug e motorcycle, with a 62.6-inch wh eelbase a nd a claimed dry weight o f 560 pou nds . Yet despite th at bulk, seat height is just 30 inches. To transform th e 90-horsepower vent ure engine into the 143-horsepower V-Max eng ine. Yamaha engineers added larger valves with sm aller stem s, th e intake valves now measuring 30.5mm compared to the Venture's 29mm a nd the ex haust va lves measuring 25m m compared to 24mm. Val ve stems a re redu ced in dia me ter fro m 6.5mm to 5.5mm to reduce airflow o bst ruction in th e ports. T he la rge r va lves are opened by ca mshafts with lon ger durat ion and hi gh er lif t (276° a nd 8.0mm for intake an d exhau st) th an Ven tu re ca ms, a nd are closed by stronger valve sp rings. Th e p isto ns a nd wri st pins a re lighter a nd th e crankshaft a nd co nnectin g rods are mad e stro nger by a new hardening a nd hea t-trea ting p rocess. T he V-Max has four 35mm downdraft Mikun i carburetor s compared to th e Venture's 34mm carbs 1 J '~'J 'l 'J )1 I ((( ")~ I ; r r r rr r r r and th e two carbs on each side of th e engine are linked by a tube fitt ed with a servo-contro lled bu tterfly va lve. At about 6000 rpm the bu tterfly valves begin to open; a t about 8000 rpm they're fully o pen, allowi ng each cylinder to dr aw fuel fro m two carbs instead of one. The resu lt is a gr eat increase in power a t higher rpm withou t any sacr ifice o f po wer at lower rp m . Yamaha ca lls th e system " V-Boost." T he V-Max has a 9500 rpm redline compared to the Venture's 7500 rpm red lin e. Th e V-Ma x is, without a n y doubt, th e stro nges t-accelera ting stock moto rcycle ever produced. T h e power availa ble is incredible wi thin the context of th e mach in e's broad po werban d a nd street-lega l no ise levels. Th is ma ch in e delivers th e perfor mance of a race bike wi th a ll the civility o f a normal street machine. It will happ ily id le a nd lea ve stop signs a t slo w speed a nd burble a lo ng with city traffi c. Th en , wi th a twist o f th e wri st, it will smo ke the rear tire a nd wh eelie a nd blast out o f sigh t, leaving behind on ly a snaking black tire mark a nd th e sme ll o f tir e rubber in the air. The su rp rise is that th e VMax is as sta ble and secure in fast corners as it is. This mo to rcycle. despi te all its massive power and ,bulk, d oes no t wobble o r wallow or tr y to slam th e rid er to the gro u nd a nytim e th e th ro tt le is opened . T he chassis. whi ch has littl e in common with th e -Ven tu re. has been redesigned to su it the bigpo wer, a nd it does a good job. But th e V-Ma x has one stra nge cha racteristic, p rod uced by the VBoost system. If eng in e rpm is a ny where near 6000 rpm as th e rider enters a sweepi ng corner, th e V-Max V-Boost system beg in s to open a nd th e motorcycle accelerates even if the rider is holding steady thrott le. It 's similar to a machine with a turbocha rger; un der certa in co nd itions th ere doesn' t seem to be a d irect co nI' I. I II t ~ r I I I I .• .., .• ' ,I.; I .' . l . nection between the throttle twist-gr ip a nd wh at the engine is doing. T he V-Max is not a road-racer replica , a nd wo n 't flick back a nd forth th ro ugh a set of ess turns th e wa y an FJ I IOO will. Its cornering clearan ce, while adequate, isn ' t o u tstandi ng. Things wi ll dra g in corners. And th e rider tryi ng to hustle thi s monster-bike do wn a canyo n road or around a roa d co u rse durin g a p ress p review day ca n never forget tha t he' s piloting a big . long mot orcycle. Indiscr im ina te throttle use in tight cu rves is an invi tati on to troub le. But giv e th e V-Max a stra ig hta way, turn on th e throttle, a nd nothing th is side o f a P ro Stock dragsrer o r a lowflying m issile is going to giv e th is Ya ma ha a run for its money. Th e V-Ma x, in its own way, is king o f the (stra ig h t-line) stree t. Wh at remains to be seen is how man y peop le will bu y it. • Yamaha V-Max Engine t y pe . • •. . . U quid- cooled . D OH C fou r-stroke V -4 Bore x stroke . • . . . . .. 7 6 x 6 6mm Displac em ent 11 9 8 cc 1 0 .5 : 1 Compression ratio Carb u ret ion ... (4) 3 5 m m Mikuni CV Ho rsepower . . .. . .. • . . . 1 43 bhp @ 9000rpm Torque 89.7 Ib .-ft. @ 7 5 0 0rpm Valves per cy linder . •... ... ... 4 In take valve size . .. . . .• 30.5mm Ex haust va lve size . . • .. . . 25 m m Int ake li ft 8 .0mm Exha ust lift 8 .0mm Incl uded valve ang le 36° In t ake valve timing 38-58° Exhaust valve t iming . . .• 68-28° (measuring pt.] . • • • .. •. 0 .15mm Ignition Elec tronic Lubrication Wet sump Redline • . • . . . . ... . .. . 9500 rpm rpm @ 60mph • . .. . . . . 3750 rpm Gear ratios Primary 1 .775 :1 (87/49) Final 2 .851 :1 (21 /27x33 /9) 5th .• . . .. .. . 0 .928:1 (2 6/2 8) 4th 1 .076:1 (28 /26) 3rd 1 .347:1 (31 /23) 2nd 1 .n2:1 (39 /22 ) 1st 2 .529: 1 (4 3 / 17) Calc ulated speed in gears at redline 5th 1 5 1.5 m ph 13 0.7 m ph 4 th 3 rd . . .. •..... . .•.. 104.4 m ph 2 nd 79.3 mph 1 st • . .. . . . . . .. . . . . . 55.6mph Fram e . . Mild steel. double cradl e 29° Rake Tra il 4 .7 in . Tele sc opic Front sus pens ion f orks Fork tube d iameter 40mm Front w heel travel .. . . . • . 5 .5 in . Rear suspensio n • . .. . D ua l sh ock sw in g arm Rea r wheel travel . . .. . •. . 3 .9 in. Fro nt brakes " (2) 11 . 1 -in . discs Rear brake 11 . 1-in. disc Front wheel 2 .15x18 in. Rear wheel 3 .50x18 in. 1 10/90-18 Front t ire Rear t ire 1 5 0 x90-1 5 Dry weight 560 Ibs . Wheelbase 62.6 in. 4 .0 gal. Fuel capacity Ground clearance 5 .7 in . Seat height 30 in. GVWR 1100 Ibs . Co lo rs .. . .. . • .. .. . Deep scarlet. dark amethyst Retail price $5299 19

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