Yamaha SZR660 is a sport bike with a 659 cc (40.2 cu in) single-cylinder engine, produced by Yamaha Motor Corporation from 1996 to 2001. It was built in Italy by the Italian Yamaha importer Belgarda. It shares its engine with Yamaha's XTZ660 Ténéré line of dual-purpose on/off-road motorcycles, but employs this engine within a Supermono package.

Yamaha SZR660
ManufacturerYamaha
Parent companyBelgarda
Production1996–2001
PredecessorSRX600
ClassSport bike
Engine659 cc (40.2 cu in) four-stroke, SOHC, liquid cooled, 5 valve, single
Transmission5 speed
Brakes320mm Brembo, with 4 piston Brembo caliper
Wheelbase1410mm
DimensionsL: 2,040 mm (80 in)
W: 740 mm (29 in)
H: 1,140 mm (45 in)
Seat height770 mm (30 in)
Weight159 kg (351 lb)[citation needed] (dry)
Fuel capacity14 litres

The 660 engine incorporates a five-valve cylinder-head. There are three intake and two exhaust valves. The bike is designed so that the smaller valves have a larger area at a lower weight than a four valve system and allow maximum intake flow and velocity.

A fuel pump is mounted on the bottom of the fuel tank to lift the contents of the tank to the twin carburettors. The fuel system incorporates one slide carb and one butterfly carb. These are operated sequentially by a manually adjustable system.