1983 Suzuki XN85D Turbo. Owner: Cliff Schoening, Bremerton, Washington.

It would be entertaining to find out how much this little turbo cost Suzuki, as in development and manufacturing expenses versus sales. Probably it was a heckuva lot. In the very early 1980s turbo-mania was in the air, and Honda and Yamaha were the first out, with the four Japanese manufacturers prone to following one another.

Remember the Universal Japanese Motorcycle" Four cylinders in line, preferably with an overhead camshaft or two. Well, this was the turbo version, and while Honda used the OHV V-twin CX500 for its turbo, the rest were UJMs. In 1981 Suzuki came out with two 650cc UJMs, the chain-driven sporty E and the shaft-drive commuter G. Similar, but different. And Suzuki realized that this two-valve (per cylinder) motor was rapidly becoming obsolete, replaced by the four-valver. So how could it get a little more use from the powerplant" Put it in the Turbo!
For the Turbo the engineers took the G?s one-piece forged crankshaft running on plain bearings, instead of the E?s roller bearings. Apparently plain bearings are smoother running. But the three 650s all had those two-valve heads, and twin overhead camshafts, that are the pretty much the same. However, everything on the Turbo?s engine, from connecting rods to cylinder studs, was strengthened.

Amusingly, when looking at the magazine spec sheets for all three bikes one notes that they all have a bore and stroke ...