Cycle News - Archive Issues - 1970's

etition! Yamaha paid more than lip service to the enduro label with the IT 400C with a proven chassis and engine combo the Yamaha people added accoutrements that spell "enduro" fr om chain tensioner, rock guard, skid plate, sparse lighting to rubber booties. The IT is the best Japanese enduro/six day motorcycle on the market. By Larry Langley AMARA was ge ne ra lly credited wi th deto nating th e tr ail bike explosion w ith the intro ducti o n of the DT-I so lo ng ago (can it be eigh t years alre ad y ?). Many mod els have co me and go ne fro m Yam ah a, including m an y so cal led " en dure s." Mean wh ile , the Yurpean m an u factu rers produced m ost of the highly co mpe titive enduro o r Six Days type mo dels which were gobbled up by a deman ding ridi ng publi c . Ho n d a became t he firs t Jap anese manu facturer to o ffe r such a serious enduro bike with th e introduction o f th eir MR-1 75 foll o wed b y the MR-250. Yamaha countere d with t heir XT /Tf-50 0 , as a respo nse to t he thumper revi val. Now Yamaha has t he bi g bore off road m ar ket co mp letely co vered wit h the IT 400C. Man y enduro riders ha ve been waiting fo r months fo r t his bike foll owing its publicity picture debu t . (Dealers received just one each from the initial shipment with more on the way .) The Yamaha IT 400C ranks at, o r near, the top of its class depending on personal preference. Mak e no mistake , the new Yamaha is a serious enduro /Six Day s motorcycle. It will win enduros with t he right rider aboard. The bes t part is t ha t it do esn 't take an Expert to ride it. Un like some h igh-stru ng motorcycles, the IT 400C is a completely tractable ride, thanks to a combination of co mpone n ts. The 397cc engine is basically th e same as the 400 MX with three important changes. The first is the addition of a fly wheel to tame the power pulses down, The second is a quieter and so mew ha t restrictive exhaust system th at further tames the engine (which wasn't all that peaky in the first place) . The third important modification wa s the addition of a wide ratio transmission more suited to enduro and off ro ad riding in general. Some of the desert racers will undoubtedly be interested in this bike, or at least the transmission. Stock, it will do about 85 mph with no sweat. Low gear will pull down to a fast cra wl b ut it could come down one more tooth on the countershaft for more enduro versatility. That would still leave it with a top speed of 75 or so . More than enough. Desert ra cer types will probably leave the geari ng alo ne, or go the other way. Yamaha has cho sen not to eq uip the bike with the new air forks as on their y Z but you won't miss them. After changing fork o il to 15 weight (a mixture of 10 and 20) we both thought the forks were superb. Th ey soaked up all th e soft st u ff and still wo rked when crashing in to the rough. Wish I cou ld say th e same for the rear suspension . The monoshock uni t o f the IT 400C comes with a lit tle over seven inches of travel but didn 't feel quite right. We co u ld n ' t put our fmg er o n ex actl y what was wrong bu t th e monoshock seemed harsh. Some dialing in by a savvy dealer may co rr ec t th ings . It w o uld probably be a mist ake to set jt up .lik; th e .d;~ert ~;Icers LARRY LANGLEY do. En duro ridi ng is q u ite different and at d ifferen t speeds over more de mand ing terrain. Yamaha didn't ski mp o n the goodies, though . A nic e big 3.1 gal lon plastic tank ca tches th e eye im media tely . A screw on ca p wh ich doesn 't lea k hides a nice b ig ho le fo r easy filling. The tank is t ransparent so y o u can see how much gas is le ft . The sha pe ma y displease some rid ers . It is fair ly wide at t he rear , and if you are th e type who likes to grip the tank wi th yo ur legs yo u won 't like the sh ap e. A cha nge to a fat /ski nny type tank will straighten things out fo r yo u if yo u're so inclined. The 8.5 inch tr avel forks are protected wi th a very nice set of fork covers to keep those seals from digestin g dirt. (A must for eastern or northern en d uros where mud ea ts sea ls alive.] The front DID rim (the good DID) is laced to a magnesium hub whi ch has a speedometer drive attached. It app ear s th e drive will fit reg ular MX hubs also. A Bridgestone 3 :00 x 21 knobby is fitted and worked su rprisingly well . For desert en d uros a six-ply tire for rock protection would be a good idea. Just a speedometer is mounted; no tach is fitted nor needed. A skimpy-looking skid plate is underneath but closer examination reveals surprisingly good case protection, at least from below. Side protection is minimal and if you are concerned abo ut ro cks at tacking the magnesium side case , a better accessory plate can be had for a reasonable price. The front fe n de r co mes eq u ip pe d with an add-on extens ion for more pro te cti o n from mud and such . Nice touch . A large 35 watt hea dligh t is fitted along with a small end uro type taillight. The bike is not street legal by an y sense of th e imagination but co me Greenhorn time, t here will be a number of them sporting license plates. A wire rock guard offers a means to stuff foam for rock prote ction ; otherwise it 's more cosmetic than an ything. The side covers come off with th e removal of one screw, revealing dual air filters fed through rubber scoops tha t in take fro m under th e sides of the seat. Should be fairly waterproof. The exhaust is quiet and as I previously mentioned, a little restrictive. That's not the whole story ; it could be worse. Yamaha supplies with the bike a kit for California only; a tailpipe cov er which has a teeny little hole for the exhaust to exit. It may be su per quiet, but it has to choke off any horsepower th e bike puts out. Also included in the kit are two intake p lates with smaller holes for res tr ict ing the air into the filter . I wo nder if t he b ike will even run with th e kit installed. Seems like overkill. A forestry ap pro ved spark arrestor is included so Smokey won 't ge t y a! Now for th e n it ty gri tty . Ho w do es it go? Right fin e, The engine is an enduro rid er 's deligh t, to rquey yet abl e to ge t it o n whe n required. Six Day riders will tune fo r more horsepo wer bu t mos t enduro riders will be co n ten t with th e amp le o utput of th e sto ck engine. It clim be d so me pretty ca bby steep hill s and it had p len ty of lo w _ .end .gTlln t. .11 n o t ove rly light at aro und 2~9. Ibs: dry .'s bu t it wasn 't p on der o us either. Bombin g d own some sand washes wi th desert type whoopers was no problem, just si t back and dial it on. Th e monoshock seemed vague at times and transmitted some harshness in the cho ppy st u ff. Ground clearance was quite good wi th 10 in ches clai med . The high pipe helps things out here. Since it tucks over the engine it is completely out of the way of the rider, exit ing jus t behind the right number plate. The spokes required only minor adjustment after 150 miles which was a relief. The tank de cals peel off rather easily spoiling the looks. Once they start to go, yo u might as well take them completely off. Fenders are blue plastic to match the tank, and should be reasonably unbreakable . The 38mm Mikuni carburetor has a healthy appetite for pre-mix. A lot of ri ders will go to an even bigger tank for long races. All in all, Ya maha has pro duced a motorcycle that will provide some serious competition in the big bore enduro class. They now offer a co mplete variety of motorcycles for any taste. What next? Probably an IT 250 if the 400 goes over well. It can 't miss. . . • Specificat ions DIMENSIONSIWEIGHT Overall length Overall width O""rall height Wheelbase 83 .26 in. 36.02 in. 46 .06 in. .56.1 in. Minimum Ground Clearance 10.04 in. Seat height {unloaded I Dry Weight ENGINE Bore/stroke Displacement Compression ratio Lubricating system CARBURETION TVpe 34.84 in. 249 lb•. .85 x 70mm 397ce 7 :57 to 1 p

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