Ducati Diana Mark 3
The Ducati Diana Mark 3, also known as the Ducati Diana SuperSport and commonly referred to as the "Ducati Mark 3", is a single cylinder bevel drive SOHC motorcycle produced by the Italian manufacturer Ducati from 1962 to 1966. It was a higher performance version of the "Ducati Diana" and sold to the American market only. In 1963, Cycle World described it as ""the fastest, and nearly the smoothest, standard motorcycle in the 250cc class"". It was replaced in 1967 by the "Ducati 250 Mark 3". History. Following the success in racing of the 250 F3 , and using an engine based on that of the racer, Ducati introduced its first 250 cc road bikes at the April 1961 Milan Fair. The bikes were offered in two versions, the touring "Monza" and sports "Diana". The Diana didn't sell well in the US and in 1962 the American importers, Berliner Motor Corporation, persuaded Ducati to make a higher performance model, the "Diana Mark 3". Berliner had previously requested a 250 Scrambler to replace the 200 Motocross. The scrambler's engine was in a higher state of tune than the Diana, and this engine was used in the  Diana Mark 3. The engine had a larger carburettor, higher compression ratio and a hotter camshaft. the Mark 3 also shared the scrambler's electrical system, using a flywheel magneto and no battery. The frame was finished in blue and the rest of the bike was blue and silver. As there was no battery side panels were not fitted. In 1965 the model received the big valve head that was used on the European Mach 1 and the larger 29 mm carb the Mach 1 used. The bike was restyled for 1966, sharing the same angular styling of the 160  Monza Junior and 350 Sebring. Following criticism of the kickstart arrangement with the rear-set footrests, the bike was changed to have higher bars and footrest in the normal position. A new design Grimica front brake with an air-scoop was also fitted in 1966. The Diana Mark 3 and the Mach 1 were replaced in 1967 with the 250 Mark 3. Technical details. Engine and transmission. The single cylinder bevel drive OHC engine was of a vertically spilt unit construction and had alloy head and alloy barrels with austenitic liners. Ball bearings were used in the main bearings and  roller bearings for the big end. Hairspring valve springs were used to close the valves. Bore and stroke were giving a displacement of . Compression ratio was 10:1. Larger valves were fitted in 1965. Claimed power output was @8,300 rpm, giving the machine a top speed of . Fuel was delivered by a 27 mm Dell'Orto SSI carburettor on early models and was increased to 29mm in 1965. Wet sump lubrication was used and ignition was by flywheel magneto. Primary drive was by helical gears to a multi-plate wet clutch and a 4 speed gearbox. A 5 speed cluster was  fitted from 1965. Chain drive took power to the rear wheel. Cycle parts. The single cradle frame used the engine as a stressed member. Rear suspension was by swinging arm with twin 3-way adjustable Marzocchi shock absorbers. At the front telescopic forks were fitted. Brakes were drums, the front being diameter and the rear .