Yamaha’s baby WR250F enduro model gets a healthy revamp to improve power and overall performance. We tested it in a frosty and VERY cold Welsh forest…

Yamaha’s WR250F is by now an iconic model across the globe: a strong workhorse of a 250F with its motocross derived chassis and unique, rearward slanted engine it is an everyman (or woman) bike.

Yamaha has come back strong in recent years pumping development time and effort into different models each year and making dramatic changes, most recently to the YZ450F. For 2018 they turn their attention to the WR250F.


The rearward slanted 250cc four-stroke WR engine has a host of changes for 2018. 

New porting in the head works with a redesigned air intake funnel, which essentially makes the engine suck and blow air better to produce more top-end power. 

A new camshaft and valve springs boost low-to-mid-range power, Yamaha claims. 

A flat-top piston design and diamond-like coated, shorter piston pin reduces friction. 

The crank is reworked for improved balance ratio (helping those revs) and a new nickel chromoly steel connecting rod helps broaden out the power spread and improve reliability. 

Combined those changes make significant, and much needed, differences to the WR250F’s overall performance. 

You can hold gears longer and rely on one gear for longer to rip through the woods.

The characteristic bogging down on a 250F when you get into a corner and ask for power without changing gear is ironed out. If I’m honest, it feels like a bored-out 300cc four stroke from five years ago. 


A revised ECU now sends 3D mapping to the fuel injection system and works with all the above changes to produce a broader and stronger spread of power. 

These are comprehensive changes to the WR’s engine, which have a very real effect on performance. 

It produces a sweet-running motor through the revs and particularly at low revs, in technical and slow riding where older 4T models were prone to stalling or coughing. 

The 2018 WR 250F is alert and always ‘picked up’ whenever asked during our test, hot or cold. 

The clutch has a minor change, a redesigned push lever makes it feel smoother.

The kickstarter mechanism is removed leaving just the reliable electric start button on the bars.

Chassis tweaks 

The chassis is based around the YZ250F MX model with a central beam now 12mm wider at the widest point, Yamaha says, and with new engine mount brackets and re-positioned footrests. 

The WR’s chassis feels stiffer than a steel back-bone type common on many enduro models, but not too stiff just arguably more accurate and better suited to fast, rough terrain. 

Weight issues? Well the wet weight remains the same 118kg/258lbs in standard form with EU road homologation kit fitted – the stock bike tested here weighs a claimed 113kg/249lbs. 

Yes, it is heavier than other 250F models but realistically does a few kilograms make any difference to how fast I can rip round a Welsh wood? Not a chance. 


Yamaha’s continued use of KYB forks and shock set-up is an example to other enduro manufacturers. 

Sure, we know the reasons behind making standard bikes softer, but when you ride a standard bike with forks like this it makes you question why other manufacturers can’t match it. 

With slight improvements to the 2018 kit, the WR250F holds a consistent line through traditional enduro terrain where some stock bikes quickly become a handful. 

The forks cope with a range of bumps, taking the big hits but not standing too firm when it comes to smaller bumps in corners where you need feel for front grip. 

That said, in standard settings I found the shock too lively and liable to rebound too much, kicking the back of the bike up. 

We had the benefit of testing a tweaked bike with the sag sorted and a few clickers stiffer which iron-out the problem.

Akrapovic add ons

There’s always the debate when you get a new bike: where best to upgrade? If our test is anything to go by you’ll want a pipe at least, ideally the whole exhaust system. 

We tested three versions in all: the standard machine, one with an Akrapovic slip-on pipe and also a the Akrapovic/GYTR full system. The latter two had the engine mapping tweaked via the Yamaha Power Tuner to suit. 

With the standard pipe and end can fitted the 250F is quieter but feels softer, less responsive off the throttle and is audibly gasping more for air through the air box.

With just the muffler upgraded you get an improvement in engine response, pick-up off the throttle and of course sound. 

The new engine works better with each step, working best of all with the header and muffler replaced with the Akrapovic fitted. 

Performance isn’t night and day different, simply it becomes a better tool for the job — like you were trying to chop carrots with a butter knife and then suddenly someone gave you a sharp knife. 

The Akrapovic parts aren’t cheap, £566/£353 for the muffler and header respectively in the UK. 

In the USA Yamaha promote a GYTR/FMF choice of a header pipe and two mufflers but the similar spec to the one we tested is a similar price also. 


The 2018 WR250F commands respect and a place in this varied enduro world of ours. 

The 2018 model is a significant upgrade: sharper and now with a strong engine performance it is a contender in the 250 market. 

A more powerful and freer-revving engine brings new life to the bike — smoothed out fuelling make it more useful. Good looking? No question with those blue rims.

Points of Interest

Well-tuned KYB suspension

Rearward slanted 250 four-stroke engine

Reworked engine for better spread of power

Stiffer chassis suits fast, rough terrain


  • Engine: 250cc, 4-stroke, liquid-cooled, DOHC, 4-valves
  • Bore/stroke: 77.0 mm x 53.6 mm
  • Transmission: six-speed
  • Suspension: KYB telescopic fork/KYB shock, fully adjustable
  • Wet weight: 118kg/258lbs
  • Wheelbase: 1446mm
  • Seat height: 965mm
  • Fuel capacity: 7.5litres/1.6Imp Gal



Credit Enduro21.com