YX600 Radian

Manufacturer	Yamaha Motor Company
Parent company	Yamaha
Production	1986 — 1990
Class	Naked bike (standard)
Engine	598cc, air-cooled, DOHC, inline-4
Top speed	125 mph (201 km/h)[1]
Power	66 hp (49 kW)@ 9,500rpm (claimed)[1] 56 hp (42 kW)@ 9,500rpm (rear wheel)[1]
Torque	38 lb⋅ft (52 N⋅m) @ 7,500 rpm (claimed)[2]
Wheelbase	54.7 in (1,390 mm)
Weight	198 kg (436 lb)[1] (wet)
Fuel capacity	12 L; 2.7 imp gal (3.3 US gal)
Oil capacity	2,200 ml (2.3 US qt)
Fuel consumption	4.9 L/100 km; 58 mpg‑imp (48 mpg‑US)

The YX600 Radian is a sport/touring motorcycle manufactured by the Yamaha Motor Company between the years of 1986–1990. Except for the suspension, the rest of the Radian was a parts-bin motorcycle and came equipped with a slightly detuned for mid and low-end torque version of air-cooled, inline-4 which came from the Yamaha XJ600 that was also along with the Radian used in the Yamaha FZ-600 Sport Motorcycle (precursor of Yamaha's FZR series of performance bikes), as well as smaller carburetors and frame from the 550 Maxim.^[1][2] Cycle World obtained for the Radian a 1/4 mi. time of 12.76 @ 103.8 mph (167.0 km/h) and 0 to 60 mph (0 to 97 km/h) acceleration at 3.8 seconds.