1. 35 years heritage. Built to customize.
Anyone who was old enough to ride a motorcycle in the 1970s will remember the fanfare that
greeted the launch of the original Yamaha SR models. Inspired by the dual purpose XT500 which
was launched a few years earlier, the single cylinder SR400 and SR500 were announced in
1978, and went on to become some of Yamaha’s most popular and enduring models.
With their relaxed torque output, slim and agile chassis design and classic styling, the
Japanesemarket SR400 and Europeanmarket SR500 became firm favourites with enthusiasts
who were looking for a simple machine that captured the very spirit of sports motorcycling. In
many European countries including Germany, Austria and Belgium, groups of SR500 owners
formed enthusiasts’ clubs, many of which still run to this day. To underline its appeal, the SR500
went on to win consecutive ‘Moto of the Year’ awards from Germany’s Motorrad magazine – one
of the highest circulation motorcycle titles in Europe. During the same period the bike was
establishing a cult following in Europe and Japan, with many SR models being handed down
from father to son.
Enduring appeal since 1978
Meanwhile, in Japan, legislation relating to the motorcycle licensing system in the mid 1970s had
created demand for 400cc models, and so the SR400 became a top seller in its home market.
Virtually identical to the SR500 but running with a shorter stroke to achieve a capacity of 400cc,
the SR400 has continued to attract massive interest in Japan over the last 35 years, with
thousands of owners and enthusiasts turning up to SR rallies throughout the country.
What is also interesting is that more than half of the owners of the SR400 in Japan are younger
than the bike they ride! Users born after 1978 now make up the majority of owners in Japan,
which demonstrates clearly that this timeless motorcycle has an enduring appeal with the newer
generation of riders.
The return of a legend
For 2014 the return of the SR will spearhead Yamaha’s growing Sport Heritage line up, which
offers today’s riders the opportunity to experience the joy and pleasure associated with simpler
and more traditional designs.
Yamaha’s classic big single has a genuine heritage and pureness of design that sets it apart
from some other ‘retro’ models. There can be no doubt that the SR400 is the real thing, and with
an authentic engine and chassis specification and original kick start mechanism, this
charismatic twinshock thumper is aimed at the many riders who are looking to rediscover the
very soul of motorcycling.
2. For many riders, the character, soul and image of a machine is far more important than its
0100km/h acceleration figures or potential lean angle. Having been brought up with the ready
availability of high performance motorcycles all around them, an increasing number of today’s
riders have decided that what matters to them are the fundamental qualities such as simplicity,
ease of use and timeless design. With its relaxed torque, light and agile chassis and sheer
mechanical beauty, the SR400 is designed to appeal to those riders who are looking for a
motorcycle with a real heritage and character, and one which fully engages its owner.
In addition to its appealing character and easy performance, the SR400 also offers many
possibilities for those riders who want to customize their machine, whether that involves adding
a few bolton parts or going the whole way and creating a café racer, street scrambler or bobber.
By offering a return to the fundamental values of biking, and instilling a new pride of ownership
with the rider, the SR400 is ready to make friends with a whole new generation of owners that
were born after the bike made its original debut some 35 years ago.
Ideal for customization
The interest in customization is growing, and many of today's riders are looking to create their
own unique motorcycle by using special parts. With its twin shock chassis and single cylinder
aircooled engine, the SR400 is the ideal starting point for any customization project.
With its simple design, this timeless motorcycle can be transformed into a café racer, bobber or
street scrambler, allowing the owner to create his or her own unique special.
ENGINE Aircooled 4stroke singlecylinder engine
With its pulsing power delivery, throbbing exhaust note, strong physical presence and
mechanical simplicity, the big single holds a special place in the hearts of motorcyclists all over
At the very soul of the SR400 is an aircooled 4stroke single cylinder SOHC 2valve engine
which is technically almost identical to the original design, with a few exceptions.
The SR400 runs with a bore x stroke of 87mm x 62.7mm and a compression ratio of 8.5:1, and
this well proven formula gives an excellent torque output that allows the SR400 rider to
accelerate strongly from low revs without having to downshift. Also contributing to the SR’s
healthy torque output is a largecapacity air cleaner, as well as a big 47mm intake valve and
optimized flywheel mass, which work together to give the SR400 an effortless and relaxed
Fuel injection for easy starting and good economy
3. The major difference between the original engine and the reborn powerplant is the use of a new
fuel injection system, which allows the bike to conform with current emissions regulations, and
also makes the SR400 easier to start than the original model.
This compact and simple new fuel injection unit delivers smooth engine running in a variety of
riding conditions, and it occupies the same space as the original carburettor to maintain the
original looks of the engine. Another advantage of this new fuel injection system is that it ensures
excellent fuel economy, allowing the rider to achieve optimum range from the 12litre fuel tank.
Our engineers wanted to ensure that the 2014 model is true to its original character, and so the
only way to start the new SR400 is to kick it! Riders who may have owned an original SR400 or
SR500 will remember that kickstarting the older models required something of a special
technique which could take some time to master.
However, the good news for the new generation of SR400 owners – and also for older riders
who may be returning to this Yamaha big single – is that the new fuel injection system ensures
much easier starting. The bike now runs with a newly designed transistor ignition system that
generates a better spark which also helps when starting the bike up. An indicator on the right
side of the cylinder head shows when the piston is in the best position for starting, and a
decompressor lever on the left side of the handlebars supports the rider in starting the engine
Beautifully finished aircooled engine
As well as its relaxed and easy torque delivery, another everlasting attraction of this engine is its
sheer mechanical beauty. With its large aircooling fins, shiny crankcases and gracefully curving
exhaust pipe, this big single is a classic design in every sense of the word. In an era when many
engines are hidden behind fairings, the sight of the SR400’s big aircooled engine is a joy to
To prevent discolouration of the bigbore exhaust pipe its exterior surface has been treated with
a special nanofilm coating, while the polished engine cases feature a clearcoated buff finish to
maintain the gleaming looks of this classic powerplant.
3way catalyser with oxygen sensor
Hidden inside the SR400’s chrome plated muffler is a 3way honeycombtype catalyser coated
with platinum and other precious metals, and this system – together with the new fuel injection
system – allows the aircooled single cylinder engine to exceed current EU emissions
4. Engine Technical Highlights
400cc aircooled 4stroke single cylinder engine
Simple and effective SOHC 2valve design
Bore x stroke 87mm x 62.7mm
8.5:1 compression ratio
Relaxed torque for easy riding
Compact and simple fuel injection system
Excellent economy with proven reliability
Kick to start system
Decompressor and piston position indicator for easy kick starts
Dry sump lubrication with oil carried in the frame
Largecapacity air cleaner
Easyaction clutch lever
Chromeplated exhaust system with 3way catalyser
CHASSIS Tubular high tensile steel semidouble cradle frame
Staying absolutely true to the original layout, the 2014 SR400 is equipped with a compact and
slimline semidouble cradle frame which perfectly complements the character of the
singlecylinder engine. This proven design is manufactured from tubular high tensile steel that
offers the optimum balance of strength, rigidity and weight, giving an agile feel and easy handling
Oil in frame
The SR400’s frame has been designed to carry the engine oil which runs through the main
downtube and into the engine, and this oilinframe design offers a number of advantages over a
wet sump system. Pumping losses within the engine are reduced, and because there is no need
for an oil sump beneath the engine, the SR400’s ground clearance is higher. This design also
allows for a slimmer body, which gives plenty of potential options for riders who want to build
their own custom bike.
Plush front and rear suspension systems
The SR400 is equipped with traditional upright front forks that give 150mm of wheel travel for a
smooth ride and easy steering. At the rear end this classic big single is fitted with a proven twin
shock system that offers 100mm of suspension movement. Together with the wellpadded dual
seat, the smooth action suspension ensures a relaxing ride, making the SR400 one of the most
comfortable ways to get about in the city or countryside.
Classic 12litre teardrop fuel tank
5. Throughout its long history, the SR400’s fuel tank design has remained largely unchanged, with
the only real ‘update’ over the years being different paint and graphics. The SR400 is equipped
with the same familiar teardrop style fuel tank which is virtually identical to the original design,
with the exception that the 2014 tank offers a capacity of 12 litres.
The focal point of the graceful teardrop tank is Yamaha’s classic tuning fork logo, and the plain
colour scheme is highlighted by a simple ribbontype band that runs around the tank’s sides.
Front disc brake and rear drum
The SR comes with a drilled front disc which is slowed by a modern 2pot caliper. Braking at the
rear end is provided by a sealed drum brake, and this proven front disc/rear drum combination
delivers smooth braking performance with plenty of feel.
Balancetype centre stand
It is anticipated that the SR400 will attract many owners who will want to carry out a variety of
maintenance jobs themselves, such as routine inspections, customization projects and tyre
changes. In order to facilitate this work in the garage at home, the SR400 is fitted with a
balancetype centre stand which makes maintenance easier and more convenient.
Lightweight aluminium rims with 18inch front and rear tyres
The latest reincarnation of the SR400 is equipped with 18inch spoked front and rear wheels that
perfectly match the character of this traditional big single. These stylish wheels are equipped
with lightweight aluminium rims which ensure low unsprung weight for smooth suspension
Chassis Technical Highlights
Light, slim and agile chassis
Classic style with timeless good looks
Potential to customize into café racer, bobber or street scrambler
Tubular high tensile steel semidouble cradle frame
Spacesaving oilinframe design
Telescopic front forks and twin rear shocks
12litre fuel tank with classic Yamaha tuning fork logo
Spoked wheels with lightweight aluminium rims
18inch front and rear tyres
Front disc brake and rear drum brake
Balancetype centre stand
Chrome plated mudguards, headlight rim and grab bar