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The first 2 pictures on the top row show image sketches for Yamaha’s first trail project, which had the code number YX047, submitted in March 1967. The third picture is from one of the clay proposal models. It had a drooping fuel tank. The frame design was already more or less final but as a whole this model was rejected as it was thought not to be attractive enough. Number 4# picture on the top row is the forerunner of the DT as we all know it. The image is already shaping up.

Second row first 2 pictures show a mock-up of the previous model. As can be seen, the exhaust was interfering badly with the riding position. On the 3^rd picture the routing of the exhaust is modified but there is still no heat-shield, whilst on the last picture the exhaust is properly tucked within the frame.

Lower left there is the DT1 everyone was waiting for (but they didn’t know that of course). On the right you see a version with some extra chrome plating, which was rejected of course (luckily!).

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Top left is the DT1, as announced in March 1968. The picture is taken at Saddleback Motocross circuit in the USA in December that year. Pic 2# “We love DT1”; happy greetings from this family, which must have been the best homage to Yamaha’s new product. Pic 3# The DT1 is faithfully waiting for his master who must have come a long way.

Next row, the DT250 of Oct. ’70 had a matt black finish with polished edges of the engine. On the right the DT250 of June ’71.

Next row, the DT250 of Nov. ’72 and the DT250 of Dec. ’73. Now the exhaust was re-routed to cross over the cylinder head to the left side. The front mudguard was now fastened to the steering head and made from plastic. The rear suspension units now had outside oil reservoirs for better cooling. The bike leaned more to the off-road scene.

Lower left, the DT250 of Feb. ’76 had a different tank shape and the crankcases were also matt black now. The DT250 of Feb. ’77 was a completely new model. It had a duplex cradle frame incorporating the motocross proven Yamaha Monocross rear suspension. The wheel rims are now from aluminium and the drooping tank design is re-introduced, but in a much more modern way than before. Overall length of the machine is 2165 mm, wheelbase 1415 mm, weight 118 kg and the engine is an air-cooled 2-stroke 7-port torque-induction single cylinder engine, max power 21 hp @ 6000 rpm, 5-speed gearbox. Tire size front 3.00-21, rear 4.00-18