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/126851
--- ..... -- - Yamaha YZ490S - ~ 00 (Above) A five-speed transm ission. new suspension and a slimmer gas tank highlight the YZ. The air-cooled motor is refined. Engine type • . • Air-cooled. reedvalve. two-stroke single Bore x stroke • . • • . . . 87x82mm Displacement 487cc Compression ratio ... ..•. 6 .9:1 Carburetion ... .. 40mm M ikuni Horsepower .• . • • • • . . . . . . N/A Torque . • . • . . • . . . . . . . . . . N /A Starting system . . . . Primary kick Ignition .. . .... . . . . . .. .. .• COl Lubrication. . . . • • • • • • . . Premix Gear ratios Primary • • . • .• 63 /24 : 2.625:1 Final .... •• .• 48 /14: 3.42B:l 5th • • .• •• •. • 20/24: 0.833:1 4th 22 /22; 1 .000:1 3rd lB/22 ; 1 .222:1 2nd . ~ 24 /16; 1 .500:1 1st. 29/16; 1.933:1 Frame Single downtube. split double cradle Rake . • • . . .......... .• •• • 28° Trail 4.B in. Front suspension type Telescopic fork Kawasaki KX50082 (Above) A reardisc brake and K.I.P.S. are new features on the KX. (Below) A smoother powerband and plusher suspension mellows out the CR . Eng ine type . .. .. Liquid-cooled. reed-valve. two-stroke single Bore x stroke ••.•. .• B6xB6mm Displacement • ••..• . • •• 499cc Compression ratio .. . .• .. B.O:l Carburetion . . •• . 40mm Mikuni Horsepower. • • • • • • • • • • •• N I A Torque N /A Starting system .••. Primary kick Ignition • • • • . • • . . . • . • '. .. •. COl Lubrication . • • • • • • • • • • • Premix Gear ratios Primary . .. .. • 66 /26 ; 2 .538:1 Final 44 /14 ; 3 .42B:l 5th 19/24 ; 0 .791 :1 4th 21 /22 ; 0.954:1 3rd 26 /22: 1.180:1 2nd 29 /20; 1.450:1 1st 32 /16; 2.000:1 Frame Single downtube. split double cradle Rake • . •. • • • • •• •• . • • • • . . . 28° Trail • • •. . ••. • • • •• • . .• •4.72 in. Front suspension type • .. . Telescopic fork Fork tube diameter • .• • • • 43mm Front wheel travel .. •... 1 1.6 in . Rear suspension type . •. Singleshock swingarm Rear wheel travel .•. ... 1 2. 6 in . Front brakes • .. • • • • 8 .7-in. disc Rear brakes 5 .9-in. drum Front wheel • • ... .. 1.60x21 in . Rear wheel . • • • • • .. 2.60x18 in . Front tire . • • • • • • • • 80 /100 -21 Bridgestone Rear tire .. •• • • ••• 110/100- 18 Bridgestone Cla imed dry weight ... 233 Ibs . Certified wet weight .. 251.0 Ibs . Overall length • •• . . . . . . 85.6 in . Overall width • •• • • . . ... 33.5 in. Overall height . . • •..... 48.2 in. Wheelbase • ••• ••. . .. .• 58.1 in . Fuel capacity . • • • • •. • • . 2.6 gal. Ground clearance •. . . . . 13.2 in . Seat height .. .• . . . ..• • 37.4 in. Colors . . . . • . • • • • • • . . . •. White Retail price .••. • . .••••• $2649 . Fork tube diameter 43mm Front wheel travel 1 1 .8 in . Rear suspension type ..• Singleshock swingarm Rear wheel travel .•.. . . 1 2 .8 in. Front brakes • •• ••• •B.7-in . disc Rear brakes 7 .5-in drum Front wheel .. • . . . . 1.60x21 in. Rear wheel • • ••• • • • • 250xl 8 in. Front t ire . . •. .... . 80/100-21 Bridgestone Reertire .... .. ... 110/100 -1B Bridgestone Cla imed dry weight . .. 220 Ibs . Certified wet weight.. 250.5 Ibs. Overall lengt h . . . . . . ..• 85.6 in. Overall width •• .• ..... . 32.1 in. Overall height . ... •. ... 48.2 in . Wheelbase ••.•. .. . • . .• 5B.3 in. Fuel capacity 2 .5 gal. Ground clea rance • .• .• • 14.8 in. Seat height • • • • • • . . • • . 37.8 in . Colors. . . . . . . . . . . . . . . . • Green Retail price . . .••. . .. • • •$2749 Honda CR500R 14 Intake Sys tem (F.A.I .S.). wh ere th e ai r intake ch a m ber is locat ed underneath th e gas tank. ro u tin g clea ne r ai r to th e a ir bo x. The silver-pai nted , high-ten sil estee l frame is all new, and delivers a more forward sea ting position. It still u ses a si ngl e front downtube th at sp lits into a double cradle where th e exha ust head pipe mates 10 the centerport cyli nde r. T he rear Un i-T ra k suspen sion system still uses an adj usta ble stru t (wh ich Kawasa ki recommends not be ad j us ted) w ith a rocker arm . (T ha t's unli ke the KX I25, whi ch no lon ger uses th e strut .) Th e Kaya ba rea r shock ha s 22 rebound adj us tment "cl icks, " fo ur h igh-speed and 14 low -sp eed ad j us tme nts (all ex ternal ); th at 's the same as last year 's model. T ravel is 12.8 inc hes . U n li ke th e rear sus pe ns io n. th e fro nt 43mm Kavab a for ks have a new feature, th e T~avel Co ntrol Va lve (T CV). T o m ake dam pi ng ac tio n more smooth and progressive. the T CV increases dam ping as th e fork com p resses. Front whee l travel is 11.8 inch es. Th e air-adj us ta ble fork ha s three ex tern a l preload an d 14 co m press ion damping sett in gs. The h ydraulic rear di sc brak e is new for '86 with the ca lipe r mounted so lid ly to the to p of th e swi ngar m . T h e master cylin de r reservoir is mounted to the fra me d irect ly a bove th e brake peda l, out of harm's way. Other new features include resh aped fenders. a rebu ildable a lu m in um silen cer , a ligh ter flywh eel and a stronger chain g u ide. Riding Starting big-bore. two-strok e motocrosse rs is never fu n . but o f th e three. Eng ine type . ... . Liquid-cooled. two-stroke. single Bore x stroke • •• •. .. 89x79mm Displacement 491 .4cc Compression rat io ... •• . . 7 .0:1 Carburetion . • • •• • 38mm Keihin Horsepower . • • . •. . 56.2 bhp @ 6500 To rque 48.5 lb .- ft. @ 6000 rpm Starting system Primary kick Igni tion COl Lubrication . . • . . . . . . . . • Premix Gear ratios Primary 63 /25 : 2.520:1 Final . •... ... 51 114: 3 .642:1 5th 19/ 24: 0 .791:1 4th 21 /22 : 0 .954:1 3rd 23 /26 ; 1. 150:1 2nd 25 /18 ; 1. 38 8 :1 1st 2B /16 ; 1 .750:1 Frame Single downtube. split double cradle Rake • • •. • . . . • .. . . . . . . . 27.3° Trail •• • • • . • .. • .• . . . . . . • 4 .4 in. th e Yamaha is th e eas iest to sta r t. The kick starter is exce lle n t a nd th ere is no cha nce o f th e rid er smas h ing his foot or sh in on th e foot peg at th e bottorn of th e stroke. Usua lly, about four kick s bring th e Yamaha 10 life when' Front suspension type • . . . Telescopic fork Fork tube diameter .. •. .. 43mm Front wheel travel 12.0 in . Rear suspension type .• . Single. shock swingarm Rear w hee l travel .• • . . . 12.6 in . Front brakes • •• . • • • 9.4-in. disc Rear brakes 5 .1 -i n , drum Fro nt wheel 1.60x2 1 in. 2 .1 5xl B in. Rear wheel Front t ire .. •• ...•• 80 /100 -21 Bridgestone M-41 110/100-18 Rear t ire Bridgestone M-42 Claimed dry weight • . . . . 223.8 Ibs. Certified wet weig ht . . 248.5 Ibs. 86.6 in . Overall length Overall w id th . .... .. . • •32.5 in . Overall height . .. . •. • • •48.0 in . Wheelbase . . ... .. • •• • • 59.1 in . Fuel capacity ..•.• •.••. 2.2 gal . Ground clearance 13.9 in . Seat height •• .. .• . . . . . 37.4 in. Co lors . . • • •. . . ..... . . . • • • Red Retail price ...... . . • . .. $2698 cold, or two when the engine is hOI. It takes th e Yamaha a lon g time 10 warm up and rea ch operating tempera tu re. a n d i n th e m eantime. the Yamaha is prone to fouling spark plugs ...,... we h ad that problem twi ce. Ii