Yamaha YD-1
Pioneer twin
Notwithstanding its relative lack of experience in the two-wheeled field, Yamaha had hit the ground running with its initial model, the DKW RT 125-inspired YA1 125cc two stroke single. The prototype YA1 had been mercilessly tested around the clock for 10,000 kilometres before it went into production to be sold under the curious title of Red Dragonfly. Teams of sales representatives were sent throughout the length and breadth of Japan, riding Red Dragonfly models, to sign up dealers. It was no simple task for a brand primarily associated with pianos, as the bikes were expensive compared to the competition, and Yamaha’s terms of sale were strictly cash on delivery. By July 1955 the Yamaha Motor Company had been established as a separate organisation to the main musical instrument company, with 100 employees that turned out 300 motorcycles per month. By this time extensive development had seen the power output of the YA1 rise from 5.5hp to 9hp, and soon a 175cc version, the YC1 was added. Somewhat brashly, the company entered both models in the Mount Asama Hill Climb, a blast up a volcano north of Tokyo, and won not only the 125cc class, but the 250 class as well. Sales of both models soared, but it soon became clear the YC1 had a manufacturing fault in the silencer which stifled the engine. To rectify the problem, the company dispatched mechanics armed with a ‚
hammer and punch to call upon every single owner of a YC1, whereupon breather holes were pounded into the baffles to cure the problem! That’s customer service for you. The expansion into the 250cc market was therefore a logical step, and Yamaha management had their eyes on the German Adler MB 250; the highly successful parallel twin two stroke dating from 1954. However while the initial inspiration may have come from the German design, the Yamaha engineers, after successfully petitioning company president Genichi Kawakami to be given a free hand in the final specification. This was duly granted and full sized drawings were created to allow engineers to construct prototypes in time for the second running of the Mount Asama Road Race of 1957. Officially, the only Adler feature retained was the overall design of the crankcase, and the Asama bikes used full cradle tubular steel frames with swinging arm rear suspension and telescopic forks, whereas the Adler employed plunger rear and leading link front suspension. For the Asama event, which had new rules for 1957, Yamaha entered two teams. The A team used a YA 125 and a YD-A 250 with a bore and stroke of 54mm x 54mm, while the B Team used a 125 and a YD-B with a revised bore and stroke of 56mm x 50mm. Like the Adler, the 250’s cylinders were steeply included, with generous square finning, both engines running a compression ratio of 9.5:1. A single Mikuni carburettor with a remote bowl was used. Ignition was by magneto on the right side of the crank, with the clutch mounted on the transmission countershaft, unlike the production YD-1 model which had the clutch on the left side crankshaft, Adler-style. To cope with the ash surface, 2.75 section studded off-road tyres were fitted to the 18 inch wheels. To the delight of the fledgling company’s management, Yamaha dominated the Asama event, finishing 1-2 in the 125 class and 1-2-3 in the 250 class. In a speech to the Yamaha workforce, President Kawakami said, “Since we lacked experience in this type of business (motorcycles), we had to study the types of products we would have to make. In our efforts to minimise setbacks and shorten the time from entry to profitability, we observed factories in Germany. After examining various types of motorcycles, we made our first 125cc model, the YA-1. We were able to start out confident that, after thorough investigation and research, we would never be overtaken by our competitors.” He went on to say that the company aimed to be the leading motorcycle manufacturer in Japan by 1959. From an initial output of 200 bikes per month at their Hamakita factory which employed just 274 people, the number had swelled to more than 1 million annually by 1975, with more than three quarters of that figure exported, and with a workforce of more than 8,000.
Naturally the US was seen as a key export market, and as early as 1958 Yamaha sent five of their YD-A 250 twins to contest the grandly titled Catalina Grand Prix, a race over a rutted gravel track on the resort island off the coast of California. Lead rider Itoh delighted the company by finishing sixth. The production YD-1 that had been released in 1957 in a rather unusual décor of brown and grey used a pressed steel backbone frame with a tubular steel swinging arm controlled by non-adjustable shock absorbers. At the front was a conventional telescopic fork. The engine was suspended from the chassis and retained by mounts at the rear of the crankcase and by a bracket connecting the rear of the cylinder barrels. The twin exhausts finished in long tapered megaphones. Like the Adler, the YD-1 sported generous mudguards and a fully enclosed rear chain, as well as a sumptuous dual seat. In a further step towards overall cleanliness, the carburettor was completely enclosed in a cast alloy shroud, like several of the European models such as Maico, Adler and DKW. With a petrol/oil mix in these days before forced lubrication became a two-stroke feature, this kept the engine cases and the rear of the machine free of oily muck. Another apparent nod to European practise was the use of 16-inch wheels front and rear. Instrumentation consisted of a Yamaha-badged Auto Meter speedometer with trip meter. 12 volt electrics and a standard push-button electric starter were practical inclusions that made good marketing sense, and turn signals front and rear were also standard equipment. The pressed steel chassis YD-1 lasted only a year or so before a completely revised YD-2 version appeared in December 1958 with a tubular front downtube, lighter mudguards and a larger fuel tank with chromed side panels. The subsequent YD-3 was almost identical except for slightly larger brakes and white-wall tyres. This model is most notable for being the first to use the Yamaha tuning fork motif on the tank badges. The YD-2 coincided with the setting up of a dealer network in USA, with separate distributors on the East and West Coasts. As early as 1958, Cooper Motors in Los Angles independently imported and distributed Yamahas, and became the West Coast distributor when the Yamaha International Corporation was established. In America, the YD-1 was marketed as the Electra with a retail price of $565.00. By comparison, a new twin-carb 175cc Puch sold for $440.00, a 250cc MZ for $570.00, and the 200cc Parilla for $549.00. But Yamaha was just getting started, and really raised the bar in the quarter-litre category with the sporty YDS-1 (initially marketed as the 250S) of late 1959, with 18hp on tap at 7,500 rpm and the company’s first five-speed gearbox. Yamaha claimed the YDS-1 was derived from the Catalina racers, with a duplex cradle frame, twin carburettors, 18-inch wheels and the 56 x 50 bore and stroke from the Asami ‘B’ racer. The basic styling of the YDS-1 would be carried through to a successful range of high performance 250 twins that would dominate the segment for the next decade.
Our thanks to OLD GOLD MOTORCYCLES (02) 4574 2885 for the opportunity to photograph this extremely rare motorcycle.