The XR250R was introduced pre 1981, and was originally equipped with a variation of the engine that had powered the XL250S since 1978. For 1983 the model was dropped from Honda's line-up, but came back in 1984 with a completely new engine dubbed the "Radial Four Valve Chamber" (RFVC) engine. The original 250 cc (15 cu in) RFVC engine had a bore and stroke of 75 mm × 56.5 mm (2.95 in × 2.22 in), but in 1986 this was changed to 73 mm × 59.5 mm (2.87 in × 2.34 in). 1986 also saw the adoption of a large, single carburetor rather than the dual progressively opening carburetors of the 84-85 models. In 1996 the engine of the XR 250R, the mainstay of the XR range, was updated and now produced 19 hp (14 kW) at 8100 rpm. Changes included a new crankcase with better engine mounts (which incorporated the swingarm pivot) for a stiffer chassis, smaller exhaust valves to address a problem with cracking cylinder heads, and an improved automatic decompresser for easier starting. Although the XR250R was always quite heavy compared to its 2 stroke competition and both front and rear suspension were rather basic, it proved reliable and likable and was successful as an entry-level off-road machine. The XR250R was discontinued after 2004.
This street version of the XR250R was built to conform to USA Department of Transportation regulations for street legal motorcycles, but was sold worldwide. It had road legal lights and tires, a steel fuel tank, keyed ignition/steering lock, lower seat height and other minor changes. Some 40 lb (18 kg) heavier, it had reduced off-road ability. It shared the XR250R's RFVC 249 cc (15.2 cu in) engine, but with a different carburetor and 3 mm (0.12 in) smaller exhaust headers to meet emissions requirements. It was manufactured from 1991-2007.
There was a Brazilian equivalent named XR 250 Tornado made from 2001 to 2009 (until 2012 for export) for the local market and regional exports to other South American countries but also available in Mexico and Central America. Its engine was the same 4-valve DOHC air-cooled single fitted to the CBX 250 Twister/CBF 250, but the exhaust was dimensioned to improve low-end torque with the sacrifice of 1hp resulting in a 23hp rating.