Yamaha XTZ 660 Tnr


Make Model

Yamaha XTZ 660 Tnr




Four stroke, single cylinder, SOHC, 5 valve


660 cc / 40.2 cu-in

Bore x Stroke 100 x 84 mm
Cooling System Liquid cooled,
Compression Ratio 9.2:1


TEIKEI  Y 26 PV / 3YF 00 carburetor


Transistor Controlled 

Starting Electric

Max Power

46 hp / 35.5 kW @ 6000 rpm 

Max Power Rear Tyre

42.9 hp @ 6400 rpm

Max Torque

55.9 Nm / 42 ft. lb @ 5000 rpm


5 Speed 

Final Drive Chain
Gear Ratio 1st 2,583 2nd 1,588 3rd 1,200 4th 0,954 5th 0,792

Front Suspension

43mm Telescopic forks

Rear Suspension

Monocross adjustable for preload, 5-way rebound damping

Front Brakes

Single 282mm disc 4 piston caliper

Rear Brakes

Single 245mm disc 1 piston caliper

Front Tyre


Rear Tyre


Oil Capacity 2.6 Litres
Dimensions Length 2265 mm / 89.1 in
Width   885 mm / 34.8 in
Height 1355 mm / 53.3 in
Seat Height 865 mm / 34.1 in
Wheelbase 1495 mm / 58.9 in
Dry Weight 169 kg / 372.5 lbs

Wet Weight

195 kg / 429 lbs

Fuel Capacity 

20 Litres / 5.3 US gal

Reserve 3.5 Litres

Consumption Average

 16.7 km/lit

Braking 60 - 0 / 100 - 0

 14.7 m / 40.8 m

Standing Mile  

 14.0 sec / 145.3 km/h

Top Speed

 167.5 km/h / 104 mph

Road Test

Motosprint Group Test 1992


Fourth generation: New 5-valve 660cc engine
Eight years after the first Tnr, Yamaha continued the dream with the XTZ 660 Tnr, following Yamaha's tradition to incorporate the latest engine and frame technology.

Yamaha used a sophisticated five-valve, liquid-cooled engine which first seemed to contradict the simplicity of the concept, but guaranteed reliability, minimum maintenance, improved environment friendliness and a good 48 hp.
The new Tnr was slimmer and less rugged than before, following the trend to increased road usage versus offroad usage at the time. For example the suspension strokes were shorter and the fuel tank was more compact, with 20 liters capacity.

In 1991 the XTZ660 appeared, the last model of the single cylinder Tnr. This model no longer has much in common with the first Tnr. The petrol tank shrank again to 20 liters and the suspension travel was shortened to 220mm at the front and 200mm at the rear. The whole appearance of the XTZ660 model was lower, heavier and longer than the original 1983 model.

More than the appearance, the new engine characterised this Model. The first single cylinder with five valves provided a agreeable engine characteristic The engine is not quite as flexible as that of the original Tnr, but in the middle and upper range it clearly had more power. The oil tank was moved again into the frame - same as the XT500 - and water-cooling provided more stable engine temperature control. The somewhat longer wheelbase provides better straight line stability at high speed and the dual-piston front disc brake provided better stopping power. 

Altogether the XTZ660 is a good-natured, solid Enduro which does not, however, have much in common with the concept of the first Tnr. For trips on desert routes, which was the original idea, it should only be used with caution. In 1994 Yamaha added a broad fairing with double headlights, but this did not have much impact on sales of the XTZ660 Tnr. Thus production was stopped in 1999.
Yamaha now had no model between the fast twin-cylinder XTZ750 and the new light single cylinder machines.




Yamaha XTZ660 Tnr: the all-purpose thumper now has a middle inlet valve, a water jacket and revised everything else. Dirt animal Tom Crees went to the launch in France.

Yamaha claimed the first three places in the Paris-Dakar this year, so they must know something about off-road bikes. With the Culf war delaying the scheduled UK launch of the completely redesigned XTZ660 Tnr single we went to France where Sonauto, the French Yamaha importer, had some pre-production models for evaluation.

Yamaha have increased mid-range torque and top end power over the 1990 600 Tnr by upping the capacity to 660cc and, for the first time on a single, using a five valve head. A bigger single is more prone to heat distortion so to keep temperatures stable, liquid cooling has been introduced and this also keeps engine noise down. Bolted to the bottom is a whopping great skid plate that not only prevents entry to the sump by a foreign object such as a rock, but will protect the engine from damage in an unscheduled trip down the road on its side.

 The motor is a stressed member of the new diamond-pattern frame which, Yamaha say, increases rigidity. Carrying the oil in the frame dispenses with the oil tank, allowing a narrower seat area which is also reduced in height by a full inch to 34'/:>in (Yamaha quote 34.1 Ed). The cockpit area has a new instrument panel recessed into a Paris-Dakar style fairing which does a fair job of deflecting air off the rider. The sit-up-and-beg riding position results in considerable wind blast at high speed but tucking in behind the screen alleviates this.

The 660 is very comfortable despite the bulbous Tnr fuel tank,  it's been slimmed down in the rear section to keep 'leg spread' to a minimum. The seat extends up to the fuel tank in the kind of smooth contour likely to protect one's gonads in a rapid de-acceleration situation.

The aluminium rear carrier is the business with all the tie hooks and brackets your bungee straps need. It also has a passenger grabrail which doubles as a convenient grappling point for pulling the bike out of the mire should you become over-ambitious in your off-road riding.

As with most big bore trailies the 660 Tnr feels tall, but once underway is no problem. The new power characteristics mean a very flexible engine (it'll pull from 3,000rpm in top  without transmission snatch), with little rider input needed to get the best out of it. Clutchless, first gear wheelies are a cinch when lifting the front for an off-road obstacle or showing off on the street. There's no point revving out in every gear; short shifting is the way to go, but if the engine does bog down a bit and you need some instant zap then a dab of the clutch will have things back on song.

Mixing with aggressive French drivers the Tnr proved a formidable tool, flowing with Paris rush hour traffic in top gear up to an indicated 175kph (105mph-ish). There wasn't much engine braking so it was down to the single discs front and rear to haul up 370lb of dry Tnr (plus varying quantities of fuel, oil and rider). The front brake was spongy, without much feel to the action, but it had the desired effect. The rear brake had a good, progressive feel to it.

The front end had a vague, wishy-washy feeling and above 70mph a weave set in. It was nothing alarming and didn't increase with speed; simply stiffening the rear rebound damping cured it, which outlines the significance of experimeriting with the suspension set-up. Vibration levels were very low due to the combination of the engine balancer shaft and rubber-mounted bars and end weights. The mirrors were effective and worked at all speeds.

Fuel consumption worked out at around 40mpg but that was with hard riding; I'd expect around 50mpg with more normal use. The 20 litre (4.4 gallon) tank should therefore be good for over 200 miles.

One gripe was with the non-self-cancelling indicators. Following lunatic French photographer Patrick Curtet, well know to PB testers for his fluent riding style and last-second directional changes, I found that life was made more interesting than necessary by his constant failure to cancel his indicators.

Off the autoroutes the Tnr coped with all situations. Fast, winding, country roads were gobbled up effortlessly, the quick steering making it easy to chuck into bends. The Dunlop Trailmax tyres did a fine job and never produced any awkWard moments. Trail tyres are always a compromise, though, so if you don't ride off-road a smaller front rim and road tyres would further enhance the handling to make a great scratcher's bike.

The Tnr is obviously no serious dirt tool but as long as you realise its limitations a lot of fun can be had. Forest road-type going and trails are no problem but in deep mud or sand the 660 overheats. This is immediately counteracted by the electric fan.

The Tnr makes an ideal all-round, do-it-all motorcycle. Its user-friendly engine, super handling and multi-purpose abilities should appeal to many types of rider: commuters, despatch riders, tourers. When I can no longer live with the potential licence-eating properties of my EXUP then the Tnr would be the kind of bike I'd via Tom Crees