The Yamaha XT660 is dual-purpose on/off-road motorcycles released by Yamaha Motors as a replacement for the XT600.

Yamaha XT660R
ManufacturerYamaha Motor Company
PredecessorXT600
ClassDual-sport
Engine660 cc liquid-cooled, 4-stroke, SOHC, single-cylinder, 4-valve, fuel injected
Bore / stroke100.0 mm × 84.0 mm (3.94 in × 3.31 in)
Compression ratio10.0:1
Power35 kW (47 hp) @ 6,000 rpm
Torque58 N⋅m (43 lbf⋅ft) @ 5,500 rpm
Transmission5-speed chain drive
SuspensionFront: Telescopic forks
Rear: Monoshock
BrakesFront: Single disc
Rear: Single disc
TiresFront: 90/90R21
Rear: 130/80R17
Spoked tubed wheels
Rake, trail28° / 113 mm (4.4 in)
Wheelbase1,500 mm (59 in)
DimensionsL: 2,260 mm (89 in)
W: 895 mm (35.2 in)
H: 1,500 mm (59 in)
Seat height895 mm (35.2 in)
Weight181 kg (399 lb) (wet)
Fuel capacity15 L (3.3 imp gal; 4.0 US gal)
Oil capacity2.9 L (3.1 US qt)
RelatedXT660Z Ténéré

It is a development of the original XT series ('X' stands for 4 strokes, 'T' for TRAIL), a line of motorcycles inspired by those used on the Paris Dakar rally. The first XT was released in 1976. The XT660R is the standard Enduro model ('R' stands for racing).

A five-valve version of the 660 cc engine was used in a number of MZ (MuZ) motorcycles, including the MZ Skorpion, Baghira and Mastiff.

After 2015 this bike was not sold in some European countries and US.

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Yamaha XT660 X 2008 facelift

Two other versions of this motorcycle are being produced alongside the XT660R – the XT660X, a more street-oriented supermoto version, and the XT660Z Ténéré, an adventure touring version,. All versions utilize the same engine and share some chassis components.

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