Honda CBX 250S

Make Model	Honda CBX 250S
Year	1985-
Engine	Four stroke, single cylinder,, DOHC, 4 valve
Capacity	249 cc / 15.2 cu-in
Bore x Stroke	72 x 61 mm
Cooling System	Air cooled
Compression Ratio	10.5:1
Induction	PHO2R Slide valve
Ignition	CDI
Starting	Electric
Max Power	31 hp / 23.1 KW @ 9500 rpm
Max Torque	20 Nm / 14.7 lb-ft @ 9000 rpm
Transmission	6 Speed
Final Drive	Chain
Front Suspension	Telescopic forks
Rear Suspension	Swinging arm dual shock
Front Brakes	Single 240mm disc 2 piston caliper
Rear Brakes	180mm drum
Front Tyre	90/90 -18
Rear Tyre	110/90 -18
Swat Height	760 mm / 29.9 in
Dry Weight	130 kg / 286.6 lbs
Fuel Capacity	12 Litres / 3.1 US gal

The Honda CBX250RS was a motorcycle first sold by Honda in May 1983 in Japan as their new 250cc sports bike with a view to replacing the popular CB250RS. The engine was based on the XR series with particular links to the XR350 bottom end, including a six speed gearbox and the same oil pump. The stroke is also the same, but the bore reduced to bring the capacity down to 249cc. The balance shaft was also discarded, with the engine instead being rubber mounted. Unlike any other XR engine the top was given two camshafts. The bike was also equipped with dual carburettors, only one of which was equipped with a pilot circuit and which open different amounts depending on how much the throttle is twisted.

The CBX250RS-E was sold in the United Kingdom between 1984 and 1986 where it was a sales flop, being more expensive than the CB250RS which was still on sale at the time and not being notably better. The release was also tarnished with stories of bikes wearing out camshafts and rockers very quickly. In the end an estimated 300 were sold. The model had stronger sales in Japan but was soon replaced by the GB250 which was styled as a cafe racer; this model was successfully sold in Japan until the year 2000 with only minor changes, the most notable of which was the move to using a single carburettor.