When the Sei was introduced (as a 750), it was the first production motorcycle featuring a six cylinder engine. By ’78, the Sei got a bump up to 900 and a redesign that included many parts from Moto Guzzi (De Tomaso owned both companies at the time). You had to pay to play – MSRP was $5,406 in ’83 – so less than 2,000 were sold (apparently some sources say less than 80 made it to the US).
The 905cc engine produced 80 horsepower, good enough to push the 484 pound (dry) bike up to a top speed of approximately 120 miles per hour. For more on the 900 Sei, check out this profile from Motorcycle Classics.
So much power that it needs two chains!
This example is one I’ve seen before as the owner acquired it through Iconic Motorbike Auctions in 2020. He reached out to let me know that he’s now selling it because he bought an earlier Sei (750cc) that needs restoration, plus he’s working on 3 MV Agustas and he bought a ’66 Pininfarina Fiat! The owner has added a bunch of new parts and the sale includes “two keys, manuals, and a box of parts.”
Find this Sei for sale in Ann Arbor, Michigan with a Buy it Now of $19,000 here on eBay.