|Engine||644 cc, single-cylinder, four-stroke engine|
|Power||44.00 hp (32 kW) at 6000 rpm|
|Torque||39 lbf⋅ft (53 N⋅m) at 5000 rpm|
|Ignition type||Electric start|
|Transmission||5-speed manual, chain final drive|
|Brakes||Front: disc / Rear: disc|
|Tires||90/90-21 54S (front)
120/90-17 64S (rear)
|Wheelbase||56.4 in (143.5 cm)|
|Dimensions||L: 86.4 in (219.5 cm)
W: 35 in (89 cm)
H: 48 in (122 cm)
|Seat height||34.3in (87 cm)|
|Weight||335 lb (152 kg) (dry)
370 lb (168 kg) (wet)
|Fuel capacity||3.4 US gal, of which 0.66 US gal reserve (13 litres, of which 2.5 L is reserve)|
|Fuel consumption||45 mpg (19 kpl)|
Its engine is slightly larger than that of the XR600R, which debuted in 1985. The 97 x 80 mm bore engine was enlarged to 100 mm and stroked to 82mm for 644cc. With 44 horsepower at 6,000 rpm, the engine had 53 N⋅m of torque at 5,000 rpm. A gear-driven counterbalancing system helps to smooth out vibrations created by the large single-cylinder engine. The compression ratio of 8.3:1 for the four valves is aided by a single chain-driven overhead camshaft. The intake is via a 40 mm Keihin constant-velocity carburettor, reaching as low as 5.2 L/100km (45 mpg) from 12.8 liters (3.4 gallons) in the tank. The bike features a dry-sump (frame carries oil supply) engine.
The non-adjustable fork has 41mm tubes and supplies 8.5 inches of travel; the rake is 28.5 degrees, and the trail is 4.5 inches. A fork brace is built into the underside of the fender. The front carries a 21-inch spoked wheel with a 90/90 tire. The motorcycle has a single front disc brake with a twin-piston caliper.
In the back, the single-shock setup allows for preload alterations, with rear-wheel travel at 7.5 inches. The rear carries a 17-inch spoked wheel with a 120/90 tire. The rear wheel features a disc brake. The footpegs have rubber inserts, intended to appeal to urban riders. If a rider was interested in more off-road use, the inserts could be punched out, leaving saw-toothed metal pegs, which are useful in precarious situations.
Other variations of the NX650 included the NX125, NX150, NX200, NX250, NX350, NX400, and NX500.
- Honda Service Manual 88-89nx650. Honda. 1988. p. 1.3.
- Staff, The (2014-12-30). "Retrospective: Honda NX650: 1988-1989". Rider Magazine. Retrieved 2019-01-28.
- Honda NX650 Dominator Review, Motorcycle Network. Retrieved 2021-06-19