Compression ratio 9.8:1 | Production 1972–1978 Top speed 200 km/h (120 mph) | |
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Engine 747 cc air-cooled inline-6 Bore / stroke 56 mm × 50.6 mm (2.20 in × 1.99 in) | ||
The Benelli Sei is a series of motorcycles that were produced by Italian manufacturer Benelli, and masterminded by automotive designer Alejandro de Tomaso, from 1973 to 1989. Two models were made, with 750 and 900 cc displacement. The 750 was the first production motorcycle with a six-cylinder engine.
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Benelli 750 Sei
The Benelli 750 Sei was the first production motorcycle with a 6-cylinder engine and had two model releases. De Tomaso intended it to become Italy's premier sporting motorcycle and wanted it badged as a Moto Guzzi. On its launch, it received tremendous publicity overshadowing all other Italian bikes of that year. It started the trend of angular designed motorcycles moving away from traditional round forms.
The engine was based on the four-cylinder Honda CB500, but with two extra cylinders. The cylinder head fins of the Sei were squared off to provide a cosmetic individuality, but otherwise the engine is in most respects obviously derived from the Honda. The "angular, bold design" was by Carrozzeria Ghia. It produced 76 bhp (57 kW) at 9,000 rpm, had a top speed of around 127 mph (204 km/h) and was one of the smoothest European tourers.
Despite the extra cylinders, the Sei's width was kept to a minimum by siting the alternator (which, on the Honda, is at the left-hand end of the crankshaft) behind the cylinders. Cooling was improved by having air passages between the cylinders; the Sei had three Dell'Orto VHB 24 mm carburetors (the Honda CB 500 had four, for four cylinders). The vehicle appeared to reviewers as heavy and cumbersome but handled surprising well, and had a unique signature exhaust note from its six mufflers.
Production Frame numbers started at 5000.Production figures were as follows ; Series 1 . 1974 293 #5001-5293 1975 1,479 from # 5294 Series 1 ,2 1976 87 from # 6774 Series 2 1977 283 from # 6861 1978 1,058 from # 7145The Benelli 750 Six remained the only six-cylinder motorcycle in production until the entrance of the Honda CBX in 1978.
Benelli 900 Sei
In 1979, by which time Benellli had sold 3,200 vehicles, Benelli developed the 750 Sei into a 900 cc motorcycle by increasing bore and stroke, with six-into-two exhausts and a small bikini fairing used on the Moto Guzzi Le Mans. Less than 2,000 were made over four model releases. Described at the time as "outrageous" or a "flashbike". Flashbikes tended to be "rare, expensive, European, quirky, handsome and high performance". It had an original MSRP of $3,995.
It was later released as a "sport" model with a larger bikini fairing.