1971 Ducati 350 Mark 3D

Make Model	Ducati 350 Mark 3D
Year	1971 - 72
Engine	Four stroke, single cylinder, SOHC, bevel gear driven
Capacity	340.2cc / 20.8 cu in
Bore x Stroke	76 x 75 mm
Compression Ratio	10.0:1
Induction	Dell'Orto SS129D
Ignition	Points, coil, 6V30W generator
Battery	Yuasa B38 12Ah
Spark Plug	Marelli CW260N / Lodge 2HN
Starting	Kick
Max Power	24.8 kW / 34 hp @ 8500 rpm
Clutch	Wet, multiplate
Primary Drive Ratio	2.111:1
Transmission	5 Speed
Gear Ratios	1st 2.46 / 2nd 1.73 / 3rd 1.35 / 4th 1.10 / 5th 0.97:1
Final Drive	Chain
Final Drive ratio	3.214:1
Front Suspension	35 mm Marzocchi telescopic hydraulic fork
Rear Suspension	Swingarm, Twin Marzocchi shocks, 3-way adjustable
Front Brakes	180 mm Drum
Rear Brakes	160 mm Drum
Front Tyre	2.75-18
Rear Tyre	3.00-18
Dimensions	Length: 2000 mm / 78.7 in Width: 600 mm / 23.6 in Height: 940 mm / 37.0 in
Seat Height	735 mm / 28.9 in
Dry Weight	128 kg / 282 lbs
Fuel Capacity	15 Litres / 4.0 US gal / 3.3 Imp gal
Top Speed	170 km/h / 106 mph
Road Test	Ducati MK3 Group Test

Desmodromic Emerges

The narrow case Ducati single cylinders were selling well and known worldwide through out the decade. Later in the decade when Ducati introduced the wide-case production models they represented the pinnacle of Ducati singles for the times. A single camshaft that was driven by bevel gears characterized the wide-case Ducati motorcycles.

As a direct descendent of the narrow-case family, the Ducati 250cc and 350cc versions of the wide-case models were first produced in the spring of 1968. The Ducati 450cc was added in the following year. The performance and elegant mechanics of the motorcycles immediately caught the attention of motorcycle enthusiasts worldwide.

Perhaps the most famous wide-case Ducati was the Scrambler. The Ducati Scrambler motorcycle sold tens of thousands around the world, leading to its legendary status. The fast and agile Ducati Mark 3 sports model was soon joined by the Ducati Mark 3D - the first Ducati with the now famous Desmodromic valve gear on a production model.

The word ‘Desmodromic' is not actually derived from Italian but rather from two Greek roots, desmos (meaning - linked) and dromos (meaning - track). The Ducati Desmodromic system is unique in that the valves are positively closed and opened by a cam and leverage system, rather than relying on standard valve springs. The same basic Desmodromic layout continues to win world championships today and is deeply seated in the Ducati Brand identify.