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Yamaha TT 600

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Make Model

Yamaha TT 600

Year

1991 - 92

Engine

Four stroke, single cylinder, SOHC, 4 Valve

Capacity

595 cc / 36.5 cu-in
Bore x Stroke 95 x 84 mm
Cooling System Air cooled
Compression Ratio 8.5:1
Lubrication Dry sump

Induction

27mm Dual stage Teikei Y27PVX1 carburetor

Ignition 

CDI 
Spark plug NGK DPR7EA or DP7EA
Starting Kick

Max Power

45 hp / 34 kW @ 6500 rpm 
Max Power Rear Wheel 38.2 hp @ 6500 rpm

Max Torque

50 Nm / 4.7 kgf-m @ 5500 rpm

Transmission 

5 Speed 
Final Drive Chain

Front Suspension

43mm Telescopic forks

Rear Suspension

Alloy swinging arm single shock with adjustable dampers.

Front Brakes

Single 310mm disc

Rear Brakes

Single 270mm disc

Front Tyre

90/90-21

Rear Tyre

130/90-18
Seat Height 935 mm / 36.8 in
Dry Weight 138 kg / 304.2 lbs

Fuel Capacity 

10 Litres / 2.6 US gal

THE TT600 AND KLX650 represent the latest trend in big trailies IN 1991. Both are designed with the intention of being capable off-road and both are conspicuously free of Paris-Dakar gimmickry. But if their raison d'etre is the same, their conception couldn't have been more different. While Kawasaki went the brand new, high-tech route, Yamaha took the recession conscious approach and let its Italian importers, Belgarda, raid the parts bin.

Finding nothing else suitable, the Italians decided to retain the original (circa '83) TT frame and merely added some bracing around the steering column and swing-arm pivot. But for the sake of userfriendliness they ditched the old TT engine in favour of a kick only XT600K item. Again modifications have been kept to a minimum. Bigger valves, a less restrictive exhaust, a more voluminous airbox and modified carburation add a bit more pep but don't fundamentally change the engine's character.

But if money's been saved on frame and engine development it's obviously been blown big time on the suspension. Up front there's YZ issue Kayaba 43mm upside-downers, while at the rear the original TT linkage has been mated to a WR250 swing-arm and a specially commissioned Öhlins shock. Braking is courtesy of a biggish 267mm front Brembo and a 220mm Nissin at the back.

Attention to detail is generally good. The tiny frame mounted alloy passenger pegs are a joy to behold, as is the minimalist instrument console, the braided front brake line and the shrink-to-fit bash plate. The tank/seat unit and general ergos aren't bad either. At 935mm the seat is daunting for the vertically challenged, but at least once you're up there its flat profile gives a choice of botty location and spares you the inexorable trail bike slide towards the tank.

There are, however, a couple of serious oversights. The lack of hand protectors and a push to cancel indicator switch are annoying. And whoever chose the dinky handlebar mounted tool bag wasn't too bothered about seeing what the speedo was up to.

Given the bike's specification its no surprise that riding the TT feels much like being on a higher and slightly pokier XT600 with beautiful suspension and infinitely better looks. The engine is crude compared with the KLX, the gearbox is nowhere near as smooth and the clutch needs a pretty hefty pull. But it's a crudeness that's not without charm. Blap around town on the TT and despite its bastard origins you its feel you're on a thoroughbred. It's just a little bit nervy, and a touch high spirited. The brakes bite hard, the semi-knobbly Pirelli Rally Cross tyres squirm a tad and the forks dive alarmingly under braking. But next to the somewhat antiseptic KLX full of character and not a bad pose.

The only thing that seriously hampers the TT's urban aptitude is the lack of an electric starter. Its not an easy bike to start, especially when the engine's in that twilight zone between stone cold and hot. Out. of town, on anything resembling a straight road the TT is frankly a pain in the arse. But then name a real trail bike that isn't. A 50-mile run down the motorway to your favourite off-road riding area is bearable. Only masochists would want to go further.

Off-road the TT behaves better than a 135kg motorcycle has any right to. Old the TT's frame might be, but its geometry is essentially right. Whereas the KLX's front wheel seemed glued to the ground, the TT is much better balanced. But the bike's forte is its suspension. It floats over ruts and bumps and refuses to get badly out of shape. It's not a bike you'd want to be up to your armpits in mud with on a Hampshire trail, but on fast, open tracks it's OK.

Overall then, give or take a few creature comforts, Belgarda has succeeded in producing a better 'real' bigtrailie than Kawasaki. The problem is, unless you're incredibly talented, any 600 trail bike is too heavy to be fun off-road. And if it's not fun what's the point? Which is probably why the Japanese gave up trying to defy the laws of physics and started turning out tarmac-friendly Paris-Dakar replicas; and why anybody who is serious about going off-road should buy something smaller.

Chris Eva