Report From Japan
REPORT FROM JAPAN
W. B. SWIM
AT LEAST FOUR riders will come from the United States to participate in the MCFAJ 16th All Japan Moto-Cross this autumn. The New England Sports Committee has told the MCFAJ they will send a four-rider team mounted on 250cc Bultaco machines with perhaps a spare rider to boot. Some West Coast scrambles riders are also expected to compete in this Japan national event, but final arrangements are not yet complete. A Japanese team of four or so of the top scramblers will go to the U.S. to compete earlier in the year, probably in September. The MCFAJ is similar to the AMA in that it is the largest organization of sports riders in the country, licenses the largest number of competitors, sanctions the largest number of events and is not affiliated with the FIM.
A Japanese inventor has come up with a new wrinkle which he claims adds around 10 percent to the power of a twostroke motorcycle engine. Yukio Imamura has patented a system which pipes fresh air into the exhaust pipe just in front of the exhaust port. The inventor claims this air at some engine speeds prevents unburned fuel mixture from escaping from the combustion chamber but, more important, at other speeds actually enters the combustion chamber instead of burned gas which has been exhausted and would otherwise be sucked back into the engine and dilute the fuel mixture. The Motorcyclist magazine of Tokyo, Japan’s leading enthusiasts’ publication, tested a rotary-disc-valved Yamaha YG-1 on which the inventor had installed his new system. The machine was absolutely standard otherwise. Test riders report an approximate 10 percent increase in power, notching 60.78 mph and a standing start 1/4 mile in 21.5 seconds. Yamaha only claims 53 mph top speed for this model. Yamaha engineers are reportedly puzzled over the invention and tend to disbelieve it. Meanwhile, inventor Imamura has put water in the Yamaha 90cc twin’s oil tank, fuel mixture in the gasoline tank and pumps the water with the oil pump to the exhaust pipes, where it is turned into steam and increases exhaust back pressure, if nothing else, although the inventor claims it adds to performance as well (through some yet unexplained process).
With all the hundreds of models of motorcycles in the world you wouldn’t think the manufacturers could come up with much new, but Japan’s variety continues to grind out more and more. Reported this month are two from Honda, four from Kawasaki and one each from Yamaha, Suzuki and Bridgestone, plus rumors, rumors, rumors.
Honda’s newest, which ought to sell like hotcakes in the U.S., is a 160cc scrambler. The CB-160 Super Sports ohc engine is mounted in a frame just like the 250cc and 305cc big brothers and dubbed the CL-160. They are really look-alikes, too, with the distinctive twin upswept pipes on the left, squarish gasoline tank, etc. The twin carburetor CL-160 with 9:1 compression gives 13.9 hp @ 9,500 rpm for a top speed of 72 mph through four gears with top torque of 8.3 ft-lb @ 7,500 rpm. Weight is 282 pounds and the 18inch rims mount a 2.75 tire in front and 3.00 in rear. For the Japan market, a single carburetor 125cc model using the same frame and the CB-125 ohc engine gets 72 mph from 13.5 hp @ 10,000 rpm. Both are kick-started. Exports of the CL160 will begin shortly.
Kawasaki has come up with the biggest motorcycle made in Japan, the model W1 650cc. One of the first off the line was air-freighted to the U.S. in time for the motorcycle show at Daytona, where it garnered a bushel basketful of orders. Stainless steel front fender, chromed front fork, rear fender, tank panels and mufflers and candy apple red gas and oil tanks, side cover and headlight case result in a really sporty looking motorcycle. The ohv twin engine has a displacement of 38.1 cubic inches (624cc) and chums out 50 hp @ 6,500 rpm to give a top speed of 115 mph through a four-speed separate gearbox. The kick-started four-stroke engine is a dry sump type with 12 volt battery and coil ignition, single carburetor and “over-square” bore-stroke ratio: 2.86 x 2.91. A blazing 13.8 second quarter-mile is claimed for the 398-pound motorcycle. Plans are .to have it on showroom floors by the time this reaches print.
The firm’s entry in the hot 250cc race, although not officially announced yet, is a two-stroke vertical twin with dual rotary disc valves which Kawasaki officials claim outperforms Suzuki’s six-speedster in all departments. Spokesmen claim it has more than 30 hp at 8,000 rpm and will do more than 100 mph through a fivespeed unit construction gearbox, as well as a quarter-mile in less than 15 seconds. The double-cradle pipe framed sportster has a two-tone tank and two-tone seat, stainless steel front fender and chrome rear fender and is equipped with a speedometer/ tachometer unit. Front brake is double leading shoe, tires are 3.00-18 in front and 3.25-18 in rear. Kawasakis Superlube oil injection is installed. It’s the first 250 with two rotary disc valves, and a real screamer according to spies reporting from Fuji Speedway, where it was tested recently. Model designation is A-l, and although the picture shows a cast iron cylinder version there is also an aluminum alloy cylinder version in existence. Which will be produced isn’t known yet. It should be ready for the American customer within a couple of months.
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Yamaha has stuck its popular 73cc YG-1 engine in the U-5 (Newport 50) step-through frame and come up with what looks like a winner in the utility field. Only 11 pounds were added in weight for a total of 165 and the YG-1 engine was detuned down to 6.2 hp @ 7,000 rpm to keep it from running off the end of the world, and also to get peak torque down to the 4,500 rpm level. Speed through the three-gear transmission and automatic clutch is 53 mph. This rotary valve two-stroke single also has a 120 kph (74.5 mph) speedometer installed, seemingly the popular size nowadays. Since the U-5 is marketed in the U.S., there’s a chance the U-7 will be as well. Wait another month or so to see. If it’s not there by then it may never be.
Bridgestone spruced up the firm’s 90cc rotary disc valve single and came up with the 90 Deluxe. Oil injection, now dubbed Jet-lube by the firm, is the big deluxe feature, but subtle touches are evident in several other spots on this 7.8 hp, 59 mph machine. Tools are stored inside the frame, doing away with that frustrating fight to get the side cover on unless the tools are rolled up just right. On the other side, the oil tank only takes up the rear half of the space, and the front half contains the air filter, which is bolted to the cover for simple removal. A flat, streamlined gasoline tank and straightthrough muffler like those on the 175 Dual Twin give the motorcycle a sharp, sporty appearance. And it has a 130 kph (80.7 mph) speedometer, yet!
Suzuki’s new one is a single-cylinder two-stroke 250cc, but don’t rush to the dealer’s showroom to look for it. It’s a one-of-a-kind scrambler built especially for Japan’s “Mr. Moto-Cross,” Kazuo Kubo, to take to Europe with him when he left in mid-April to contest the International Moto-Cross World Championship series in the 250cc class. He tried two of the international races last year, but the scrambler just wasn’t in the same class with the competition. Although last year’s machine served as a very rough basis of this year’s model, actually the new machine is so different it should be called a new model. There won’t be any on sale this year, but if it makes a good showing in the series, look out U.S. and Europe!
Now for the rumors. To jump back up to the top, Honda is reportedly putting a five-speed 50cc ohc sports machine into production. It is designed for the overseas market and sports a pressed T-bone type frame like the 65cc models. Following the change in Japan’s driver’s license laws and traffic rules for motorcyclists, all the manufacturers here are rumored to be working on small engines around 30cc in size to power two-wheelers which will be little more than bicycles. The new regulations would allow such machines to be ridden without a driver’s license. Honda (who else) is rumored to be in front in the race, and liable to reach the market first. Honda is the most secretive, so it’s the maker which attracts the most rumors. Two more, reported previously, which are still going around from time to time are about a dohc 250cc and a dohc 650cc Four. The Yamaha 350cc twin rumor is still with us, as it has been for a year and a half, and now to join it is a Kawasaki 350cc twin rumor, supposedly the 250cc reported in this issue bored out. Then there are the even vaguer rumors: Bridgestone designers are busy on a big machine; Suzuki’s research lab is working on multiple cylinders; the Honda Research and Development Institute is studying two-stroke engines intensively; and so on and so on. Dear Lilac (with a total production in the past two months of two motorcycles) gets close to a reporter’s heart if only because he does not have to continually run his legs off checking hot rumors about what the firm is up to.
The Tokyo Metropolitan Police Department recently bought 38 Rabbit scooters. Not to chase down speeders, but for lady traffic cops and police box patrolmen to use to beat the clogged traffic in the world’s largest city.
One of the winners of the MFJ’s 3rd Moto-Cross Grand Prix was to leave for Europe, courtesy of the sponsor and SAS airlines shortly after this column was written. He is scheduled to spectate at the 500cc international moto-cross in Switzerland and the 250cc in Belgium, with the possibility of being able to stay over for the 500cc in Italy and the Spanish GP.
Yamaha shipped a 250cc road racer to Australia a while back and a week later were possessors of not one, not two, not three but four trophies at the Australian T.T. held at Calder Circuit in Victoria. The factory machine, with Aussie A. Osborn aboard, nabbed the 250cc and 350cc classes without any trouble at all and then won both the 500cc and Open classes after close tussles with Norton 500cc racers.
The MFJ officially announced that this year’s Japan Grand Prix road race will be held at the new Fuji International Speedway about three hours from Tokyo. Now we’ll sit back and see what really happens. As reported in detail last month, Honda wants the GP at its Suzuka Circuit as in the past and aren’t liable to compete at Fuji unless they have a title at stake. What is a GP without Honda? On the other hand, Suzuki says it won’t race at Suzuka unless it has a title at stake. What is a GP without Suzuki? As of the day this was being written, Suzuki has Yamaha, Bridgestone and Kawasaki with it and Honda is all alone.
An American Air Force serviceman stationed at a base near Tokyo won two classes at the 7th All Japan Motorcycle Clubman Race, the national road race sponsored by the MCFAJ. This is Japan’s Daytona — the oldest, most famous race in Japan. Again like Daytona, and unlike the FIM GP races, factory machinery was barred by the rules. Stephen Yard was the only rider among 128 entries to win two events. He took the 350cc novice race on a 305cc Honda CB-77 and then challenged the junior riders and won the junior 350cc event going away as well. The top five places in the novice races were allowed to ride in the junior race if they wanted to. Novices were limited to hopped-up over-the-counter street machines, while juniors could ride anything that was not entered in the GP last year — in other words, production racers but no works machinery. The race was the first event to be held at the 3.75-mile Fuji International Speedway near Tokyo, which is a fast circuit featuring a full mile-long straight with a huge, steeply-banked curve at the end of it. Fastest lap, and consequently the course record, was 2 min. 23.83 sec. by Keigi Mimuro riding a Yamaha to win the 250cc junior race. Yamaha won four, Bridgestone three, Honda two and Tohatsu one of the ten races. Unbelievable as it may seem, the sponsors had to order another first place trophy for the novice 250cc class. Two riders were timed by the electronic timer in exactly the same time down to 1/100th of a second at the end of a 10-lap 37.5mile race. Both Tsutomu Wada and Kunihiro Miyatake clocked 27 min. 33.36 sec. Both rode Yamahas. As far as the naked eyeball could see, they were certainly exactly side by side all the way down the straight and across the finish line. The $10,000 electronic timer saw it the same way, and the MCFAJ declared them both first place, with the next man third. So counting this, Yamaha had five winners. Yard averaged 83.75 mph in the 16-lap 350cc junior and 82.63 mph in the 12-lap novice race. Mimuro pushed his Yamaha at 91.63 mph in the 15-lap junior 250cc. Novice 250cc winners clocked 81.63 mph over 10 laps. Tohatsu rider Ichiro Ichinose averaged 80.94 in the 12-lap 125cc junior and he was followed home by Kazuo (Johnny) Honda on another Tohatsu. Masao Kanai won the 7-lap novice 125cc at 77.88 mph on a Yamaha. Yamaha rider Shogo Noguchi won the 10-lap junior 90cc at 73.75 mph and Bridgestone rider Keizo Sato averaged 74.31 mph in the 7-lap novice race. Fifty winners were junior Ryuzo Tanaka on a Bridgestone at 68.03 mph over 8 laps and novice Kenji Miyaguchi, also Bridgestone mounted, over 5 laps at a 69.06 mph average.
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During the noon break, the traditional antique motorcycle exhibition race was run over two laps. Rules were that the machines had to be at least 15 years old, and they were handicapped according to age and nearness to original condition. This was won by Yujiro Sugisawa on a 1942 Harley-Davidson 45. Following was a 5-lap sidecar race, the first time sidecars had been on a road race circuit in Japan. Winner was T. Ota on a 600cc BMW R-69S.
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The biggest scrambles race, recently, was the 13th Tokyo Moto-Cross, which saw a turn-out of 25 American military riders. Two got trophies, James Christopherson (TAS club, Honda) seventh and Ronald Pipher (TAS, Honda) ninth in the novice 250cc race. MCFAJ got 244 entries in the nine races of the day, and Suzuki riders walked off with the honors four times. Yamaha and Kawasaki each got two and Honda one. Only double winner was young Yamaha expert Tadao Suzuki, who took the Open and junior 125cc. The junior 250cc went to a 150cc ridden by Jiro Umezu. Suzuki riders Tateo Enomoto and Hideo Atomura won the junior 90cc and 50cc events.
The 32nd Yokota Scrambles pulled 92 entries and had an American winner, for a change, James Christopherson (Honda) in the junior 250cc race. The Open went to Seigi Motogi (Yamaha), a junior rider. Tsuneo Miyashiro won two of the four novice races, riding a Yamaha to take the 125cc and a Tohatsu to win the 50cc. The 250cc went to Ryusuke Nakahira (Honda) and the 90cc to Kazutoshi Kurihara (Bridgestone).
The Americans finally mastered their base track and won all but one race and all but three places at the 3rd Sagami Scrambles. Bridgestone rider Sumio Kanzaki won the novice 90cc and Japanese were also second and third, but the rest of the day was for the Americans. James Christopherson rode his Honda to wins in the Open Class and junior 250cc and Charles Ball won the novice 250cc, also Honda-mounted. Both are in the Tokyo All Stars club. ■
