Unexpected Six: 1983 Benelli 900 Sei

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1983 Benelli 900 Sei
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The Sei was the widest 6-cylinder powerplant on the market at 25.75 inches.
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1983 Benelli 900 Sei
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1983 Benelli 900 Sei
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1983 Benelli 900 Sei
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The 900 Sei wears a small fork-mounted fairing borrowed from the Moto Guzzi Le Mans, and by 1983 it retailed for a costly $5,406.
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The 900 Sei wears a small fork-mounted fairing borrowed from the Moto Guzzi Le Mans, and by 1983 it retailed for a costly $5,406.
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Owner Gary Athey and his perfect 1983 Benelli 900 Sei, which has just 17 miles on it.
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“I almost fainted when I saw all of those chrome pipes,” Gary said.

1983 Benelli 900 Sei
Claimed power:
80hp @ 8,400rpm
Top speed:
120mph (period test)
905.91cc air-cooled SOHC inline six, 60mm x 53.4mm bore and stroke, 9.53:1 compression ratio
Weight (dry):
484lb (220kg)
Fuel capacity/MPG:
4.4gal (16.5ltr)/35-45mpg
Price then/now:
$5,406 (1983)/$15,000-$20,000

In 1972, Richard Nixon ordered the development of a space shuttle program and David Bowie sang about Ziggy Stardust and the Spiders from Mars. The Summer of Love was long over, and disco, with all of its glitter and excess, was just beginning. In the same year, into this heady stew of women’s liberation and the seemingly never-ending war in Vietnam, Italian manufacturer Benelli unveiled the first production 6-cylinder motorcycle. They called it the 750 Sei — “sei” is Italian for six.

New owners

In 1971, sports car magnate Alejandro De Tomaso purchased Benelli. His immediate plan was to create a motorcycle that would be a Benelli image builder, something people would talk about and aspire to own. He handed the task to his engineers, who were given a short time frame to come up with a line of multi-cylinder motorcycles, a 500cc 4-cylinder and a 750cc 6-cylinder.

He essentially wanted the two-wheeled equivalent of his Pantera sports car, an exotic coupe powered by a Ford V8. Almost immediately, Benelli’s engineers came up with the 750 Sei, and in the fall of 1972, De Tomaso unveiled it at the Canalegrande  Hotel in Modena, Italy. Featuring sharp, angular styling to the fuel tank, side covers and fenders penned by Carrozzeria Ghia, and six chromed exhaust headers with three mufflers stacked on each side of the motorcycle, the 750 Sei demanded attention. When De Tomaso thumbed the starter button and fired the 71 horsepower six, breathing through three 24mm Dell’Orto VHB carburetors, each mounted on an aluminum Y-manifold feeding two cylinders, and revved it up a couple of times, the audience was captivated.

That audience was a horde of motoring journalists, and the subsequent press coverage created an expected stir. But months after the introduction, the new 6-cylinder motorcycles had yet to come pouring out of the Benelli factory.

Production reality

So where was the new bike? According to a late summer 1974 article in Cycle World, this is what De Tomaso did to bring the Sei to the public’s attention, almost a year and a half earlier: “In the allotted time schedule he had but one choice; copy closely a successful existing multi engine design (Honda Four), tack on two more cylinders, hang it in proven chassis geometry and do a big styling number. Spring the package on an anxious press and worry later about producing the thing, because in Italy that could never happen overnight.”

However, Cycle World editors traveled to Italy in 1974 to sample a prototype 750 Sei, and they liked what they found. “What you have in the end,” they wrote, “is a motorcycle that is not the fastest thing from stoplight to stoplight, not the quickest over Mulholland Highway, not an economy winner or a touring trickster. What it does do, though, it does with the best, and it does it with a novelty appeal and sound unsurpassed by any other machine to date. Does that make it worth more than three grand? Well … that’s kinda up to you … now isn’t it?”

In 1976, the Benelli 750 Sei cost $3,995. By 1978, only 3,200 had been produced, and by then, Honda had introduced its 1,000cc 6-cylinder CBX. Which begs the question: Was there really ever a motorcycling appetite for 6-cylinder multis? It was, apparently, a battle for superbike supremacy. While the sixes from both Italy and Japan were technological tours de force and captured attention, they didn’t set any sales records. And yet into the fray marched Kawasaki with the KZ1300.

The numbers game

Motorcycle journalists all found favor with the Benelli Sei, but the price meant sales were slim. However, Benelli decided to continue to pursue the seemingly elusive 6-cylinder buyer and upped the ante in 1978, increasing the Sei’s bore and stroke to 60mm by 53.4mm to give 906cc. The engine grew wider, too, by about 2 inches, the result of moving the alternator from above the transmission to the left side of the crankshaft. This increase made the 900 Sei the widest 6-cylinder powerplant on the market at 25.75 inches. The chain-drive primary connected to the 5-speed gearbox through a dry, multi-disc clutch (the 750 clutch was wet), and final drive was via a massive double-row chain. A Silentium six-into-two exhaust system replaced the distinctive six-into-six header and muffler system, and the three carburetors were enlarged to 29mm Dell’Orto units.

The angular design cues found on the 750 gave way to smoother and more flowing body lines, and a small fork-mounted fairing (borrowed from the Moto Guzzi Le Mans; De Tomaso also owned Moto Guzzi at the time) helped increase the 900 Sei’s wind-cheating abilities. New instruments were sourced from the Guzzi V50, and the gold-colored, 18-inch magnesium wheels courtesy of Campagnolo featured Brembo brakes; dual discs up front and, new for the 900, a single disc at the rear. Borrowing yet again from Moto Guzzi, the 900 Sei was equipped with linked brakes, with one of the two front calipers squeezing a disc when the rear brake was applied.

Following the practice of the 750 Sei, the 900 featured a double-downtube cradle frame with Ceriani telescopic front forks, and like the 750, the 900 wasn’t cheap. In 1983, a 900 Sei had a suggested retail price of $5,406. By the end of production in 1989, fewer than 2,000 examples of the 900 Sei had been built; some sources claim no more than 80 of them made it to the U.S. market.

Gary’s Benellis

In 1983, three of those claimed 80 Benelli 900 Seis landed at the late Marshall Elmer’s Lakeside Cycles, in Menasha, Wisconsin. Some 10 years had passed since De Tomaso had first unveiled his 750 Sei, and the times had indeed changed. Ronald Reagan was president, and Michael Jackson and The Police dominated the airwaves. The A-Team was on TV, and Darth Vader and the Empire were building a new Death Star in Return of the Jedi.

Back in 1983, Gary Athey was up to his elbows in engines, transmissions and differentials at Athey’s Garage in Green Bay, Wisconsin. A family business, the automotive machine shop got started in 1946. Gary bought out his father in 1970. He still owns the garage, but says he only ever goes in now to perform work on his own motorcycles, boring cylinders or cutting valve seats.

“My Dad had a motorcycle, but when I was born Mom said he had to sell it to buy a baby carriage,” Gary says. “I think I started riding a Whizzer when I was 8 years old, and I’ve owned motorcycles since I was 12. Currently, I’ve got about 20 old machines, from Ariels to BMWs, Harley-Davidsons to Indians, Nortons and Triumphs.” Plus two 1983 Benelli 900 Seis.

Usually, Gary buys complete motorcycles that require total restoration. He won’t buy a basket case that’s missing bits and pieces, because if he has to make a new part, he wants something in hand as a pattern. “I try to make them as perfect as they can be,” Gary says of his restoration philosophy. “I’ve only bought three new bikes in my life — the first was a Moto Guzzi back in 1972, and the other two were these 1983 Benelli 900s.” Plainly, Gary didn’t need to do any serious restoration work on the Benelli 900s he uncovered.

No restoration needed

Gary knew Marshall Elmer from his Lakeside Cycle shop. In fact, that’s where Gary bought his 1972 Moto Guzzi Eldorado 850 GT. Over time, however, Gary lost track of Marshall, but his interest in old motorcycles found him searching for Marshall in 2006. He eventually located him, and learned Marshall had several mini-warehouses stocked with old bikes he needed to sell.

“We started going through them and I bought a 1968 Norton Fastback and a 1967 Triumph,” Gary explains. “Then, I came across these two brand-new Benellis. The crates were all broken, and I almost fainted when I saw all of those chrome pipes, and I asked Marshall what they were.” Marshall replied that they were in fact Benelli 900 Seis.

“He said he used to carry them,” Gary recalls. “He told me that they were expensive in their day and he simply didn’t sell many of them.” Gary managed to buy one 900 Sei on the spot, but Marshall said he wanted to keep the other, together with another 1983 900 Sei that he had in parts.

“Marshall took one out of inventory in 1983 and put 153,000 miles on it. He still had it, too, but the motor and transmission were in pieces,” Gary says.

The first Benelli 900 Gary bought was black, and it showed 10 miles on the odometer. After talking to Marshall some more, Gary managed to purchase the second 900 Sei, the silver one featured here, which had 17 miles on it — all from being test ridden by the factory. When Gary picked up the silver Sei, Marshall, who was seriously ill, gave Gary the third Benelli that was in pieces. Not long after, Gary learned Marshall had passed away. “After I got the Benellis home, I put them in the shop,” Gary says. “I put the one that was in parts away, and then cleaned everything up on the two new ones. I drained the old fluids, and added all new fluids and filters. The gas tanks were clean and dry, and I put fuel in them and started them up, and ran through all five gears. “Then, I removed the gas tanks, dried them out, and fogged off the engines with Sea Foam spray. They sat for seven years until this year, when I sold the black one.”

Gary has never ridden his silver 900 Sei down the road. While he says it’s tempting, he just doesn’t want to do anything that could damage the “new” Benelli.

“I never planned on buying a Benelli 900 Sei,” Gary says. “In fact, I never even knew Benelli made a six. It was a surprise, and it was least expected, but I’m glad I’ve got, and kept, the one. My friends all thought I was nuts buying two of them.” MC


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