Yamaha SR400: Future Classic Thumper

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Bike Reviews

By BikeReview - 16 April 2021

Words: BikeReview Photography: Jeff Crow

When you enjoy older bikes, or want a blast from the past, authenticity is a major factor. The fuel-injected SR400, which arrived in JDM in 2010 then Australia, EU and the USA in 2014, has that authenticity in spades. It was originally available in Japan from 1978 due to 400cc licencing laws (the rest of the world got the 500) and was available until 2008 when emissions regulations finally caught up with the little single.

Beautiful chrome pillion grab rail and stunning exhaust system, and a kick starter!

So in 2010 it reappeared with fuel injection to replace the original carburation and to surpass emissions requirements. With demand strong, and the SR500 still selling well on the secondhand market, Yamaha decided making the SR400 available to a wider market was a good idea, including here in OZ.

The original SR500 made 36hp and had a top speed of 90mph(150km/h) but the more modern 400 is just 22hp.

The ‘new’ SR400 runs a four-stroke single-cylinder SOHC two-valve engine, with a shorter stroke than the original 500 to reach just 399cc, with a 47mm intake valve and ‘refined flywheel for ultimate rideability’. Compression is just 8.5:1, while kickstart is – startlingly enough – the only way to get the bike running, with the aid of a decompression lever and piston position window, as well as a new transistor ignition system to ensure strong spark. Yamaha stopped building the bike in 2017, resuming in 2019 to meet further pollution laws.

The decompression lever and the old school switcheblock, this is exactly the same switchblock that you will see on late 1970s Yamahas.

Old school chrome clocks look great.

The tubular steel semi-cradle frame is still used and serves as an oil reservoir, meaning no sump and better ground clearance, while the forks and rear shocks are simple but plush across a variety of Australian road surfaces – albeit almost certainly designed for lighter riders.

It’s rare to see a bike that is less than a decade old already worth more than it cost new… but that is the case with the 2014-2017 SR400…

A single front rotor with twin-piston caliper provides good stopping power, accompanied by a rear drum brake with good control and feel, while engine braking provides any additional slowing needed. You may also note both front forks incorporate mounting points for a caliper making adding an addition rotor and caliper a definite possibility.

We didn’t want to hop off the fun, basic thumper at the end of the launch ride in 2014.

Controls are simple, the 18in spoked wheels stylish and the teardrop shaped tank elegant, especially with the comfortable single piece seat.

Jumping on the SR400 it is light, belying the 173kg wet weight and feeling considerably lighter, with good balance and a nice low seat height.

The SR goes back to 1978 and is still in production, although had a break a few times to be updated, it is a legendary machine and engine, also made famous by the TT500 and XT500.

Working out the starting procedure is relatively simple, using the engine window to check piston position is top dead centre and the decompression lever to keep everything nice and easy. Then a good solid kick and the bike roars – well thumps – into life. Ensuring the kill switch hasn’t been used to stop the bike is a good place to start if the bike doesn’t get moving second try.

Metzeler 90/100 – 18 front tyre and 298mm single disc with two-piston caliper.

Having impressed everyone with your knowledge of the archaic and time-honoured process – hopefully first kick, so everyone recognises your prowess – you can set off. The clutch is light and gear engagement solid and reassuring, all the way through the gearbox.

It was brave by Yamaha to stick to kick start only but sadly that would have put off a hell of a lot o potential buyers in the LAMS market, which was a big mistake…

With 23 horses rearing to go the bike won’t win any take-offs at the lights against other motorcycles, but the 20ft-lbs of torque comes in early and continues through the rev range allowing for plenty of fun, even in traffic, where keeping the engine boiling along higher in the rev range provides plenty of kick for suburban speeds. Suspension is supple, while the bike is planted and very nimble, feeling light, comfortable and capable.

Chrome guard, they are good looking bikes, not so sure about the mirrors though they look out of place.

A great all rounder, the bike is also capable of handling the highway when needed, although obviously being naked wind will be noticeable – giving a good excuse to don your goggles, open face helmet and scarf.

With a grin plastered over my face it was with great reluctance I stepped off the bike several hours later, thinking what a great little machine the SR400 is.

The $8999 RRP price tag seemed a little steep, but the build quality of the bike is exceptional, without plastic components and the bike is undoubtedly more than a sum of its parts. And it is still worth $8000 to $10,000, if you can find one!