The Ducati 250 Mark 3 is a 249 cc single-cylinder bevel-drive SOHC motorcycle produced by Ducati from 1967 to 1974. It was initially built with the narrow-case engine, and the new wide-case engine was used from 1968. A higher-performance version, the 250 Mark 3D with desmodromic valves, was also available.
Ducati 250 Mark 3 at a glance
| Maker | Ducati, Borgo Panigale |
|---|---|
| Production | 1967–1974 |
| Engine | 249 cc bevel-drive SOHC single; narrow case, wide case from 1968 |
| Bore × stroke | 74 × 57.8 mm |
| Compression | 10:1 |
| Power | 30 bhp |
| Top speed | 145 km/h |
| Carburettor | 29 mm Dell’Orto |
| Suspension | 31.5 mm forks; 35 mm Marzocchi from 1973 |
| Brakes | 180 mm front and 160 mm rear drums; twin-sided Grimeca front from 1973 |
| Production | about 2,800 Mark 3 and 1,300 Mark 3D |
Facts in this article come from one source, the English Wikipedia page on the Ducati 250 Mark 3.
History of the Ducati 250 Mark 3
Replacing the Diana and Mach 1
Introduced in 1967, the Mark 3 replaced the American high-performance 250, the Diana Mark 3, and its European counterpart, the Mach 1. Like the Diana Mark 3, the new model used the dynamo-and-coil ignition of the Mach 1 rather than the flywheel magneto and generator of the Diana.
The Bill Hannah affair
The American motorcycle market slumped in 1967 and the Ducati importer, Berliner Motor Corporation, got into financial trouble and refused a consignment of 3,500 machines. They were sold to the Liverpool businessman Bill Hannah, who sold them to the public between 1968 and 1972, some as Mark 3s at a discount. Hannah offered no support or spares network, which damaged Ducati’s reputation in Britain.
The wide case of 1968
Fabio Taglioni had designed strengthened racing engines, culminating in the 1967 250SCD and 350SCD, Sport Corsa Desmo. For 1968 Ducati introduced new road engines based on the racing unit, keeping its wider rear mountings; these became the wide-case engines. The 250’s wide-case version had a stronger bottom end with bigger main bearings and a bigger big end, wet-sump capacity up from 4 to 5.5 pints, and an upgraded kickstart. The 1968 Mark 3 had a Tartarini bread-box tank of 13 litres with twin filler caps; a single-filler version came in 1969.
Import disputes and the 1973 restyle
Few Italian-made models reached Britain and the United States in 1970–71 while Berliner and Vic Camp were in dispute with the factory over prices, and Spanish-built MotoTrans models were imported instead. A new tank came for 1971, and in 1973 the bike received a revised dual seat, side covers, instruments and headlight styled like the 750 GT, in blue and gold, with 35 mm Marzocchi forks and a twin-sided Grimeca front brake.
The Mark 3D and the Desmo
The Mark 3D had a desmodromic head derived from the 350 SCD racers, retaining light hairspring valve springs; the rest of the engine and cycle parts were the same. In 1971 the desmo model became the 250 Desmo with café racer styling: clip-ons, a fibreglass tank and a monoposto seat in metal-flake silver, the “silver shotgun”. From 1973 it had a metal tank, different side panels and a combined seat and rear mudguard in yellow and black, and in 1974 Ceriani forks with a single 280 mm Brembo disc.
Design and features
- Ignition: dynamo and coil from the Mach 1 instead of the Diana’s flywheel magneto.
- Wide-case engine: stronger bottom end, larger sump and better kickstart from 1968.
- Bread-box tank: Tartarini’s 13-litre tank with twin filler caps.
- Mark 3D: the desmodromic version with the racing-derived head.
Ducati 250 Mark 3 versions
- 250 Mark 3 (1967–1968): the narrow-case original.
- 250 Mark 3 (1968–1974): the wide-case version.
- 250 Mark 3D: the desmodromic model.
- 250 Desmo (1971–1974): café racer version, the “silver shotgun”.
The 250 shared its chassis with the 350 Mark 3 and 450 Mark 3. More Ducatis are in the Ducati collection.
Sources
- Ducati 250 Mark 3, English Wikipedia: history, engine, cycle parts, Mark 3D
