Report From Japan

REPORT FROM JAPAN

DEPARTMENTS

JACK YAMAGUCHI

FIRST-EVER MX WIN

It is a well-known jinx in Japan that no race is won by Honda in the presence of Mr. Soichiro Honda, the supreme leader of mighty Honda Motor. But, it was not the case with this year’s Japan Motocross GP which was part of the national championship series.

The newly developed Honda was ridden by ex-champion T. Yoshimura, who finished 2nd and 1st in both heats of the senior 250cc race. By so doing, Yoshimura became the overall winner of this round as Mr. Honda (sitting beside His Imperial Highness Prince Takamatsu) watched.

The senior 250cc class event was contested by 16 riders. In the first heat, M. Takezawa on a works Kawasaki made the clearest getaway, and continued to increase his advantage. During the latter stage of the race, however, he was forced out with mechanical troubles. From then on, the race developed into a battle between Yoshimura and M. Takahashi on a works Suzuki. Takahashi managed to pull ahead of Yoshimura during the closing stage, and finished first. But, in the 2nd heat it was Yoshimura’s turn. From start to finish he displayed his outstanding riding skills to lead the entire field, smashing a strong challenge from H. Suzuki on a works Yamaha.

It was the first win ever scored by Honda in a big national motocross event.

The Japan Motocross GP is the largest and the most important motorcycle sport event in Japan. This year’s event was unfortunately run in gloomy weather, but still attracted some 30,000 spectators. The meeting was divided into three categories, namely junior, expert/junior and senior. The junior category had three displacement classes—90cc, 125cc and 250cc. Ex-

pert/junior and senior categories had 125cc and 250cc classes, respectively.

The senior 250cc class was the most important race for which the four makers of Japan entered their respective factory teams. Each maker had concentrated particular efforts on the development of their own machines for this race. Honda’s efforts bore fruit in the most efficient and impressive way.

It is now evident that this success has massively increased Honda’s confidence in this type of sport. Thus, Honda should become more aggressive to claim its own footing in the field of two-cycle motorcycles.

Senior 250cc class results 1. T. Yoshimura ............Honda 2. M. Takahashi ......... Suzuki 3. H. Suzuki ..............Yamaha Senior 125cc class results 1. M. Matsumoto ...........Suzuki 2. K. Yajima ...............Suzuki 3. H. Suzuki ..............Yamaha

SUZUKI GT 250 DISC

As already reported, the Suzuki GT 550 and 380 models are now equipped with the ram air system and a disc brake. Now the lightweight GT 250 has followed this example.

Engine layout is substantially no different from that of the standard GT 250. Maximum power is 30 bhp at 8000 rpm.

A newly designed fuel tank accentuates its overall appearance together with a front disc and large-size cylinder head.

YAMAHA SPORTS MR 50

Yamaha has recently introduced a real off-road 50cc model under the designation of MR 50. Yamaha’s smallest displacement trail model features a double cradle frame and Ceriani type front forks, just like bigger displacement brothers of the line. The engine is of the newly developed reed valve induction single-cylinder type.

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This engine, however, functions on conventional three ports with no sub transfer ports, unlike bigger displacement trail models which feature a 7-port scavenging system. A nozzle is mounted between the -carburetor and the reed valve for engine lubrication.

The MR 50 develops a maximum power of 6 bhp at 9000 rpm, and ensures steady performance at a wider range of speeds thanks to the newly employed reed valve induction system.

Compared with the Mini Enduro model, the MR 50 has become more terrain-worthy in many respects. Kit parts will be available for motocross competition.

For the technically minded, specifications are as follows: Bore x stroke, 40 x 39.7mm; displacement, 49cc; maximum power, 6 bhp at 9000 rpm; starting, primary kick; road clearance, 7.2 in.; front fork stroke, 4.4 in.; weight, 154 1b.

YAMAHA SPORTS FX 50

Concurrently with the debut of the MR 50, Yamaha’s brand-new mini sportcycle 50cc FX was unveiled for sale. Frame and engine layout is basically the same as the MR 50, but the FX 50 features more sporty details as a road sport model, represented by a long slim fuel tank. Muffler and transmission layout also adds another sporty feeling to this model. Maximum power is 6.3 bhp at 9000 rpm.

ROADRACING AT SUZUKA

Just a brief note concerning a recent roadrace at the Suzuka circuit. In the over 251cc class Honda and Yamaha are hard at it. This time, Morio Sumiya on a CB500 Four came out on top, but Meitai Motohashi really put on a strong 2nd place performance on Yamaha’s new water-cooled TR3.