Today’s Benelli Sei 900 might be pushing the definition of the term “sport bike” a bit: it’s not light, agile, or designed for pure speed. It is more of a gran tourismo, a grandiose pronouncement of Italian style and engineering, even if a few mechanical bits were artfully cribbed from the Japanese… Styling was bold as well, although it looked backwards instead of forward as we headed into the 1980s. But that makes sense, as the Sei was originally released in 1972 as the Sei 750.
Styled by Ghia and powered by an inline six that predated the Honda CBX by six years, the Sei certainly made a powerful statement of intent, announcing that a small Italian company could still compete against the Japanese in terms of engineering. Although it probably didn’t help their case that the inline six design was heavily “influenced” by the Honda CB500’s four cylinder engine, Benelli made some significant improvements to the design, narrowing the engine significantly. Cooling of the air-cooled unit was improved by adding air passages between the cylinders and the cooling fins were squared-off to provide distinctive styling.
At the time it was introduced, styling was considered very modern, with more angular lines and shapes than most other motorcycles on the market. In 1979, the inline six was bored and stroked to 906cc to give us the bike seen here. The six blaring exhaust pipes were reduced to just two, and a duplex drive train was added to tame the five additional raging horsepower…
That iteration soldiered on until 1987, although by then it was obviously outperformed by… probably everything else on the road. But was anything cooler than that straight six blaring through an open exhaust system?
From the original eBay listing: 1983 Benelli Sei 900 for Sale
Benelli 900 Sei, 11000 miles from new, very well preserved, and runs perfect. If you contact me, I can share videos of the bike running, starting from cold, etc.
This bike is being sold because I’ve purchased another Benelli Sei, a 750, that needs restoration. The bike runs beautifully, and yes, it has small cosmetic blemishes, because it used, as every bike should!
Since I purchased in 2020, I ran for ~1,000 miles. Service history includes:
1. New fluids throughout (oil changed every year)
2. Rebuilt carburetors by iconic motorcycle team
3. New tires (in 2020)
4. New windshield (old ones were cracked)
5. New tachometer and speedometer cables – THE OLD ONES WORKED, THEY WERE JUST ABOUT TO BREAK
6. New battery
7. New body panels (not visual, under rear fender, and holder for tools)
8. New magneto
9. New petcocks (only part that is not original!)
10. New side covers (original)
11. New horn (original)
12. New footrests (original)
13. New sidestand (original)
14. New turning lights (original shape, original color would be black, they are currently chrome)
15. Fixed factory issue of poor ground on the headlights
16. New headlight
17. Oil pan re-threaded (it was leaking due to over tightening of previous owner)Sale includes two keys, manuals, and a box of parts. Happy to share photos if requested.
There’s still plenty of time left on the listing and the seller’s asking price is $18,000. That seems ambitious, but this looks like a very nice example of a very exotic motorcycle. Seis used to go for a mere song, with the only real question being servicing costs and parts. Luckily, the inline six uses three carburetors instead of the CBX’s bank of six, but finding maintenance parts or bodywork could prove to be very tricky…
-tad
Nice write up, Tad! Wonder if the duplex drive chain was more “hype” than necessity? De Tomaso was quite a “salesman”.
Honestly, I’ve gotta think it’s more hype than anything else. It made a claimed five more horsepower than the 750…