Yamaha SR 400




Make Model

Yamaha SR 400


2004 - 08


Four stroke, single cylinder, SOHC, 2 valves per cylinder.


399 cc / 24.3 cu-in
Bore x Stroke 87 х 67.2 mm
Compression Ratio 8.5:1
Cooling System Air cooled
Oil Capacity  2.4 Litres
Lubrication Dry sump


BSR33 carburetor


Starting Kick

Max Power

27 hp / 17.1 KW @ 7000 rpm

Max Torque

27.4 Nm / 6.3 kgf-m @ 6500 rpm
Clutch Wet, Multiple Disc


5 Speed 
Final Drive Chain
Frame Steel Double Cradle

Front Suspension

Telescopic fork
Front Wheel Travel 150 mm / 5.9 in

Rear Suspension

Dual shocks
Front Wheel Travel 111 mm / 4.3 in

Front Brakes

Single disc

Rear Brakes


Front Tyre


Rear Tyre

Rake Caster Angle 27º
Trail 111 mm  /  4.4 in
Wheelbase 1410 mm / 55.5 IN
Seat Height 790 mm / 30.9 in
Ground Clearance 130 mm / 5.1 in

Wet Weight

174 kg / 384 lbs

Fuel Capacity 

12 Litres / 3.2 gal

The first incarnation of the SR since 1978, when it was introduced to the market SR500 (which was then presented as a more road-oriented use of the legendary XT500, launched just three years earlier), but at that time the model received a great success due to the advent of fractional motors, which made it look immediately 'dated' his single cylinder 499 cc. Initially marketed in several markets, the SR in recent years has been offered almost exclusively in Japan only as SR400,

with a shorter stroke so you can take advantage of the laws of the country of the Rising Sun that require a certain license for motorcycles up to 400 cc displacement. The SR400 was produced until 2008 and then reintroduced in 2010 with a fuel injection system in place of the 'old' carburetor.

The SR400 engine has a lower displacement, achieved with a different crankshaft and shorter piston stroke[4][5] and both models feature only kickstarting, i.e., no electric starter.

The SR400 has been marketed in the Japanese Domestic Market (JDM) since 1978 and was introduced to Europe, the Americas and Oceania in 2014. Its engine capacity complies with JDM 400 cc licensing restrictions.

The SR500 was marketed in Asia and Oceania (1978-1999), North America (1978-1981); and Europe (1978-1983) — and was not marketed in the Japanese market.

The SR was originally developed under the design credo "easy to use",[6] and when Yamaha's Technical Director wrenched his ankle while testing a prototype, easier starting became a priority — and Yamaha developed a decompression lever and sight glass system.[6]

The SR was styled by Atsushi Ishiyama with Yamaha presenting a pre-production prototype to US dealers in late 1975.[6] Ishiyma said of the bike's styling: "Our choice was to design the new SR500 with a strong family image and a strong link to our first four stroke, the XS 650 twin, which was also inspired by British design.