Yamaha s XT250 four-stroke single

Press, 24 April 1980, Page 18

Yamaha s XT250 four-stroke single

By

PETER BRITTTENDEN

Since the introduction of the first Japanese trail bikes in the mid-19605, the dual purpose motor-cycle has always been a compromise. In spite of what the name suggests, a trail bike spends most of the time being ridden on paved roads. Off-road excursions are generally reserved for week-ends and holidays. Consequently, manufacturers have designed trail bikes which are a compromise between road and off-road machines. However the road requirements are mostly given more attention.

In the last few years the degree of compromise has decreased. An excellent example of a “real” trail bike is the newly-introduced Yamaha XT2SO, an extremely versatile machine which handles the seal and the rough supremely well. The XT incorporates most of what modern motor-cycle technology has to offer. This includes mono-cross rear suspension, C.D.I. ignition, an automatic decompressor

on the motor, and a very sophisticated carburettor which automatically adjusts itself to handle either "heavy-handed” or careful, conservation- oriented throttle use. Over all, the XT is a very well-designed package. Handling, comfort,

performance, and value all receive top marks. When it was first introduced the XT was described by some observers as a small brother of the XTSOO Yamaha. In fact there are vast differences between the two machines. The larger XT, although

described as a trail bike, was only useful off the road in a modified form and in the hands of an expert rider. The XT2SO is much better suited to off-road use than the 500. With a dry weight of only 113 kg (tlie 500 weighs 140 kg), the 250 proved extremely nimble and able to cope with some extremely rough going in paddocks off the Summit RoadThe long-travel suspension proved fade-free and extremely supple. The mono-cross system does come in for criticism because of its location. Detractors of this type of suspension say the damping is reduced because the fluids lose viscosity when subjected to heat from the engine. But there were no signs of this during testing. , . Handling m the rough was excellent. Excellent ground clearance, combined with a relatively low seat height, made the bumpy tussock country on the Port Hills reasonably easy to handle. High compression and reasonably heavy flywheels make slow, careful riding off the road quite pleasurable. The motor showed no desire to stall, even at minimum revolutions. However, the motor is not a “thumper” in the old British tradition. Given a reasonable amount of throttle the XT can provide plenty of thrills. On road the XT was a real joy to ride. Like most light bikes with a reasonable amount of power, the XT was most at home on tight winding roads.

The “new generation” trail tyres proved more than adequate on tarseal and allowed amazing angles of lean while cornering. Unlike the old universal trials pattern tyres trail bikes . used to be equipped with, the latest patterns are much more versatile and much safer. In all situations the gearbox and clutch operation was perfect. The clutch provided plenty of takeup range, and the gearbox was very slick and positive. Overall the XT was extremely comfortable to ride. The relationship between handlebars, seat, and footrests was marred slightly bv the position of the bars. These caused me to stretch forward a little too much for comfort. But for a taller rider (my height is 174 cm) this would not be a problem. Vibration through the seat and footrests was minimal, although at most speeds vibration rendered the rear view mirrors almost useless. Starting, once the simple knack was learned, was easy.

Economy is very important. Like most fourstroke singles, the XT2SO is inexpensive to operate. Most owners are reporting performances between 4

and 4.6 litres per 100 kilometres.

The XT includes several features which are seldom seen on motor-cycles. One • is the louvred front guard , which is designed to pro- . tect the rider from mud and water but still allow a stream of air to pass over the motor for neat dissipation. Another is the . series of fins moulded into ■ the bottom ‘of the fork- ■ le°s. Overall, the XT2SO could be regarded as an example of what motorcycling in the 1980 s will be all. about. It is a simple, but effective and pleasant machine to ride. In terms of value for money the XT, which was supplied by Jacks Yamaha, would be one of the best buys of the year so far. It retails for $2249. SPECIFICATIONS Engine, four-stroke, single, 5.0.H.C.; displacement, 249 cu. . ' cm; bore and stroke, 75 x • 56.5 mm; compression ratio, 9.2:1; maximum torque, 2.okg m at 6500 r.p.m.; carburation, Mikuni 28mm; ignition, C.D.1.; " starting, kick; lubrication, wet sump; transmission, five-speed; length, 213 cm; width, 89cm; ■ height, 117 cm; seat height, ’ 84cm; wheelbase, 140 cm; ground clearance, 25cm; dry weight, 113 kg; fuel tank - capacity, 8 litres; oil capacity, 1.6 litres; front forks, telescopic with 20cm travel; rear' . suspension, monocross with 12cm of travel; drum brakes; tyres, 3.00 x 21 front, 4.60 x 17 rear. . L mtoo—bmi ■■neg—eogawi \