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Yamaha SR 400

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Make Model

Yamaha SR 400

Year

2010 - 11

Engine

Four stroke, single cylinder, SOHC, 2 valve

Capacity

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 Wet sump

Induction

Fuel injection

Ignition 

TCI
Starting Kick

Max Power

22.93 hp / 16.7 KW @ 6500 rpm

Max Torque

27.4 Nm / 20.2 lb-ft @ 3000 rpm
Clutch Wet, Multiple Disc

Transmission 

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 swingarm
Rear Wheel Travel 104 mm / 4.1 in

Front Brakes

298mm single disc

Rear Brakes

Drum
Wheels Wire spoked

Front Tyre

90/100-18

Rear Tyre

110/90-18
Rake Caster Angle 27º
Trail 112 mm  /  4.4 in
Dimensions Length 2085 mm / 82.1 in
Width    750 mm / 29.5 in
Height 1095 mm / 43.1 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 

12.1 Litres / 3.2 US gal

Auto-By magazine in Japan has tested the new fuel-injected Yamaha SR400 for MCN – revealing it has lost none of its charm.  

To clean the SR400’s emission for 2010 up Yamaha has replaced the carburettor with a fuel injection. It’s not a simple job though – a new exhaust with a catalyser and lambda sensor is also new (it’s slightly bigger than before), and a fuel pump is required to pressurise the injector.  

This created a problem – a bulky pump would affect the tank shape, so to get around it the fuel tank feeds fuel in to a small sub-tank under the left side panel (which is 10mm wider to cover it) containing the pump. An air-injection system is the final change to clean the exhaust gases up.

Riding the bike reveals that it’s much the same as before – the chassis might be 30 years old but at 174kg with a low, narrow seat and wide bars, it handles well. You can’t rush it – smooth corner entry and throttle opening to gently load the suspension is the key to preventing wobbles, but while it isn’t nimble it’s good fun to thread through a series of corners.

Peak torque is slightly lower, but the torque curve is fatter and more linear through the rest of the rev range, so it accelerates quicker with better throttle response, especially from 4000-5000rpm. The clutch has a lighter spring too, which makes life easier.

Sadly, it’s only sold in Japan. A real shame – as a cool, easy to ride retro commuter the SR could win a few fans in the UK.