Report From Japan
REPORT FROM JAPAN
TA125 PRODUCTION RACER
Yamaha is putting a lot of effort into its competition oriented two-strokes of late. This is especially true on the home front, and in Japan the one that is drawing the most attention is the ultra light TA 125 production racer.
Perhaps the reason this class is so popular is that 125s have been one of the most important segments of the home market, ever since the industry was founded some 20 years ago. In addition, bikes of this size offer a lot of advantages. Some of these are brisk performance, compact size, light weight, ease of handling, reasonable prices and low upkeep cost.
Couple these advantages with a growing interest in road racing and it’s easy to understand why Yamaha developed the TA 125, which is, in reality, a scaled down version of the world-renowned 250cc TD model.
The engine is a two-stroke, five-port, air-cooled Twin with an actual displace ment of 124cc. Bore and stroke is 43 by 43mm and with a 7.5:1 compression ratio, 24 bhp is produced at 12,750 rpm.
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Following a trend in the remainder of its roadracing line, the TA 125 has CDI ignition. But, unlike the larger models, a wet, multi-disc clutch is used. Both the 250 and 350 use air-cooled dry clutches. Also, a five, instead of a six-speed gearbox is fitted, probably in the interest of economy.
Tires, both front and rear, are 2.50-18s. Drum brakes are used, twin shoe unit and front and a single shoe brake at the rear.
With a weight of only 178 lb., it should be very competitive in production-type events.
YAMAHA YZ REPLICA
The YZ 637 works machines ridden by Hakan Andersson, Jan V. Velthoven and Christer Hammargren have proven so successful that Yamaha has decided to produce replica versions, designated YZ250s.
The primary reason for this move is that there is a substantial market for race ready motocrossers. Also, as the overall level of bikes improves, people are less willing to spend additional time and money making changes.
The engine is a 246cc, seven-port Single with reed valve. Bore and stroke is 70 by 64mm and with a compression ratio of 7.4:1, 34 bhp is on tap. Maximum horsepower is produced at 8000 and maximum torque at 7500 rpm. Primary kick starting, a five-speed gearbox, and CDI ignition are other notable features.
Wheelbase is on the long side at 56.8 in., and this should ensure a good deal of stability at high speed. With a dry weight of only 207 lb., watch out for this one. It has winner written all over it.
