Английская Википедия:Ducati 239 Mark 3
Шаблон:Short description Шаблон:Use dmy dates Шаблон:Use British English Шаблон:Infobox motorcycle The Ducati 239 Mark 3 is a Шаблон:Convert single cylinder bevel drive SOHC motorcycle produced by the Italian manufacturer Ducati in limited quantitiesШаблон:Sfn for the French market in 1974. The French Government has announced that they were to increase VAT on motorcycles of 240 cc and above in 1975. Ducati responded by producing the 239 to take advantage of the lower 20% VAT rate on sub-240 machines.Шаблон:Sfn To compensate for the reduced capacity, the engine was tuned to produce more powerШаблон:Sfn with a different camshaft,Шаблон:Sfn slipper piston, 30 mm carburettor and a different exhaust using a Lafranconi silencer.Шаблон:Sfn
The factory ceased production of ohc singles in 1974. The remaining stocks were purchased by the then British importer Coburn & Hughes, including some 239s, who continued to sell them until early 1976.Шаблон:Sfn
A desmodromic valve version, the Ducati 239 Mark 3D, was also available.Шаблон:SfnШаблон:Sfn
Total production was around 400 machines; 250 Mark 3s and 150 Mark 3Ds.Шаблон:Sfn
Technical details
Engine and transmission
The single cylinder bevel drive OHC engine was of unit construction and had alloy head and alloy barrels with cast iron liners and was based on the 'wide case' engines used in the racers.Шаблон:Sfn bore and stroke were Шаблон:Convert giving a displacement of Шаблон:Convert.Шаблон:Sfn Coil valve springs were fitted which was a departure from Ducati's normal practice of fitting hairsprings on the OHC singles.Шаблон:Sfn Claimed power output was Шаблон:Convert @ 7,500 rpm.Шаблон:Sfn
Fuel was delivered by a 30 mm Dell'Orto pumper carburettor,Шаблон:SfnШаблон:Sfn as used on the 750 GT.Шаблон:Sfn The engine used wet sump lubrication and electronic ignition.Шаблон:Sfn
Primary drive was by helical gears to a multi-plate wet clutch and 5 speed gearbox. Chain drive took power to the rear wheel.Шаблон:Sfn
Cycle parts
The single cradle frame was the same as the item used on the 250 and used the engine as a stressed member. Rear suspension was by swinging arm with twin 3-way adjustable Marzocchi shock absorbers.Шаблон:Sfn At the front Шаблон:ConvertШаблон:Sfn Ceriani telescopic forks were fitted. The front brake was a twin-sided Шаблон:Convert Grimeca drum on the Mark 3 and a single Brembo Шаблон:Convert disc on the desmo.Шаблон:Sfn At the rear a Шаблон:Convert drum was fitted on both models.Шаблон:Sfn
239 Mark 3D
An additional version of the 239 Mark 3 was offered, the 239 Mark 3D, also for the French market, that was fitted with a different head that used desmodromic valves.Шаблон:Sfn (A system where the valves are positively closed by extra lobes on the cam and levers rather than by a more conventional springs).Шаблон:Sfn The desmo was fitted with a disc brake on the front.Шаблон:Sfn Around 150 demos were made.Шаблон:Sfn
References
Bibliography
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- Шаблон:Cite web
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