Cycle News - Archive Issues - 1980's

Yama ha'. Interp retatio n of the modem -day four-a troka .ngle , the ng you TT800. Althou gh It ha.llm ltation ., the TTwUI do juat ebout anythi Im pr ess ion : .98 3 Yamaha TT600K Rell~·IJ ..e ll th in g li g h tn in g By Kllre1 Kramer In mot orcy clin g's own unw ritte n myt holo gy of ben ch raci ng, four -stro kes, part icul arly big, sing le-c ylin der mod els, enjo y som e of the fRost hyp erbo le-g ilde d desc ripti ons in memo ry. Their engin es are credit ed with enoug h torqu e to gh . level moun tains, c:nou _ power (or endless wheeh es and an ex- 16 haust note mellow enoug b to soothe the most savage anti-motorcyclists. While in the midst of these overrat ed rambli ngs, the more honest of the portable-seating-device racers would mumb le aside and admit that their thump ers were a shade contrar y to start at times and they were heavy enough to punch a bole in the earth if jumpe d high enou gh., Now, with the release of the Yamaha TT600 , and Honda 's XR5OO, are these things still true of four-stroke singles? Well some are but then some weren' t ~e before. 'Most of t~y's four-strokes make their serious power at higb rpm and they are still heavy. With the TT600 , Yamah a has finally fulfille d the promis e of hill-lev eling power, amazin g low-end torque and endless wheelie power. It even sounds nice. The TT ,joins the best oftoda y's four-strokes in the yes-it-has-morethan-a~motor category. A IDlXture of TT, IT, YZ and new parts make up the TT. The rear suspensio n and frame show a strong IT inOuence. IT hubs with a double leading snoe front brake make up the rolling part of the package. IRC tires inthela rgebyl S-incb sizein therea r and the regular by 21-inch size in front handle the ground work. Not for long, however, as the 600 shreds both front and rear tires in amazin gly short order. We wore out both tires on our test bike in two trail rides in the high desert area of southe rn Califor nia. Wheel contro l is handle d by a Kayaba fork in the front that is air loil ~djustabl~, but has no dampi ng adJustmentl~ the bottom o~ th~ fo~k I~g as the YZ hne does. We didn t miss It. The rear sbock is a less-sophisticated model than on the YZS also. It features only reboun d dampi ng adjustme nt. The shock is attache d to the swinga rm by a linkage similar to went It to. W h it e the one on the IT, but the TT's has a slightly different ratio. Red paint keeps rust from attacking the high-te nsile steel frame and sets of( the white plastic bodyw ork quite nicely. The sides of the fuel tank dinied a bit after use, but the white was fairly easy to mainta in. The plastic work is not shared with other Yamah a models. Contro ls are standa rd Yamah a fare. What the contro ls connec t the rider to, however, is quite special. The engine in the 600 IS a large part of its appeal . A larger bore turned what was basically an XT550 engine into a full 595cc worth of thump er. A chrome d alumin um bore is utilized in place of a steel liner. That and other weight -saving change s result in an engine that is lighter and larger than the XT550. Dual carbs, called ymS by Yamah a, feed the engine like a two-barrel carbur etor on a car. One of the carbs is a vacuum -operat ed design and the other is a cable and slide-type as found on most dirt bikes. The slide side opens manua lly and the vacuum side open as vacuum deman d dictates. Sitting on the bike gives the rider a couple of different impressions. The ergono mics are compa ct, but with a 116.5-inch seat height it is a long stretch to the ground. Startin g requires a healthy kick, but is easier than the early XR500s. It starts like any fourstroke: no, throttle unless it won't start, then full throttle and pray for your foot. The alumin um kicksta rt iever has a ding in it after many starts, but is not bent in any way - a sign of fairly easy starting . If you tip it over while hot, lit down and wait if it doesn' t start right up. Usually 10 minute s will do the trick. Once the engine has stoppe d being grump y and is willing to run without choke, it pulls away from a stop with no throttle . There is DO proble m with lack of torque or horsep ower from this engine . More power? More throule . It's as simple as that. Before we spent any time on the Yamah a elsewhere, we spent two full 8O-mile days in the desert with the TT. It roosted up anythi ng we had the conrage to point it up. And we've never had so much fun on fireroadsl 01arge into a tum and kick it down a couple of gears and the rear wheel hangs out ,like a half-miler. Despite the sheer heft of the machin e compa red to smalle r bikes, it behaved on downhills. Fast riders rode it fast and slow riders rode it slow. One of our testers rides off-road on a 175cc bike. He didn't even waotto try the big bike. When 'someo ne volunte ered to spell him, since he was riding with a Oat, he tried the TT and was quite surprised at its civility in spite of its power output . Later in the test, he felt confid ent enough on the bike to race it.

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