Suzuki GT series

The GT series is a series of two-stroke, rider and passenger, chain drive motorcycles manufactured and marketed by Suzuki for model years 1972-1977, with a range of engine capacities and cylinder counts. Certain markets received the GT380 until model year 1980.

The initial lineup consisted of the GT380 three cylinder (marketed in North America as "Sebring"); GT550 three cylinder (marketed in North America as "Indy") and GT750 three cylinder (marketed in North America as "LeMans")

Engines were piston-ported two-stroke with Suzuki's multi-point oil injection system, marketed as Crankcase Cylinder Injection (CCI) (previously marketed as PosiForce), conventional battery/points ignition system and chain-type final drive. The motorcycles featured engines with Schnuerle porting. Alternators featured a three-phase excited field type using brushes and slip rings with a wound rotor. A solid state rectifier and a mechanical three-step regulator completed the system. Previously Suzuki had primarily used a permanent magnet single phase alternator setup on its bikes so the new equipment was quite a step up for the GT series.

The 380 and 550 engines were air-cooled with a system marketed by Suzuki as Ram Air. This system consisted of a cast aluminum shroud covering a modified cylinder head to direct the cooling air.

The GT750 was liquid-cooled. Suzuki thus led the motorcycle world by being the first company to mass-produce a liquid-cooled, large-bore two-stroke engine. The GT750 was nicknamed the "Water Buffalo" in North America and the "Kettle" in the UK.

Other names were the "Wasserbuffel" in Germany, "la bouillotte" in France and the "Water Bottle" in Australia.

The 550 initially featured chrome-plated piston rings and cast iron cylinder bores. For the 1976 MY, the 550 received a system of cast-iron rings running in chrome-plated cylinder bores. This change was largely thanks to the RE5, which also used a proprietary cylinder wall plating similar to a Nikasil coating. The coating, marketed as Suzuki Composite Electro-chemical Material or SCEM, is nickel-phosphorus-silicon-carbide based, reducing weight (by eliminating a steel liner) and improving heat transfer, allowing for tighter and more efficient piston-to-cylinder clearance.

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