1973 Ducati 350cc Mk3 Motorcycle

Description

Produced by Italian manufacturer Ducati from 1968 to 1974, the Ducati 350 Mark 3 is a 340cc single cylinder bevel drive SOHC motorcycle. At the behest of its American importer, Ducati introduced the initial 350 Sebring model in 1967, a development of the existing 250cc model. The US was Ducati's primary market at the time, however designer Fabio Taglioni had concerns about the reliability of the bottom end, so the Sebring was produced in a mild state of tune. Taglioni designed strengthened versions of the engine for racing, culminating in the 1967 250SCD and 350SCD (Sport Corsa Desmo), so Ducati introduced new engines to the 250 and 350cc road bikes based on this racing engine. The single cylinder bevel drive OHC engine had alloy head and barrels, with cast iron liners. Primary drive was by helical gears to a multi-plate wet clutch and five-speed gearbox, with chain drive taking power to the rear wheel. The Mark 3’s single cradle frame was a strengthened version of the 'narrow case' bikes using the engine as a stressed member. Rear suspension was by swing arm with twin three-way adjustable Marzocchi shock absorbers, while at the front telescopic forks were fitted. Brakes were drums initially, though from 1972 Marzocchi forks and a twin-sided Grimeca disc front brake were fitted. Claimed output was 18 kW at 8500 rpm, giving the Ducati a top speed of 150 km/h. While sharing the same bore and stroke (76 mm×75 mm) as the Sebring, the Mark 3 had a higher compression ratio, hotter cam and bigger carburettor. Initially, the 1968 Mark 3 had a 'bread box' 13 litre fuel tank with twin filler caps, however a single filler version was introduced in 1969. A new-shaped tank was then fitted for 1971 and two years later came a revised dual seat, side covers, gauges and headlight, styled similarly to the 750 GT. Marzocchi forks and a twin-sided Grimeca front disc brake were also fitted in 1973. A higher performance version, the Ducati 350 Mark 3D, which used desmodromic valves, was also available. Ducati ceased production of its OHC singles in 1974. Total production was around 2300 Mark 3s and 1350 Mark 3Ds.