Yamaha 2007 YZF 250

Published: 15th February 2007

Author: Words by Sutty and Tony Marshall Photos by Sutty

Storm Trooper! Is the 2007 YZF 250 Yamaha's best MX2 missile yet? We pick the foulest day of the year so far to find out...

Being original can never be a bad thing - take Yamaha and their 250 four-stroke motocross bike for instance. The YZF250 was the first four-stroke MX2-class missile to be launched to the unsuspecting motocross market in 2001 and it wasn't until '04 that Honda, Kawasaki and Suzuki joined the race.

And while owners of the two new 250F models - the Kawasaki and Suzuki models were actually the same bike but in different colours - suffered teething problems including overheating and what was perceived to be premature valve failure, the Yamaha was a rock solid performer that outshone its competition.

But proving that motocross riders can be a fickle bunch, by the end of '05 the YZF - which was still a top-of-the-class performer - was deemed to be too long in the tooth, somewhat outdated and a little bit uncool! Luckily, Yamaha were once again one step ahead and the company that had re-vamped their two-stroke range with ally frames for '05 followed suit with their four-bangers in '06.

The zero-six YZFs certainly looked the part with their fresh frames and brand-new bodywork and initial tests led us to believe the YZF250 was a vastly improved bike over its predecessor. But as the season wore-on and tracks dried out it soon became apparent that the '06 model didn't like to turn half as well on hard, flat turns as earlier models did.

And there were other potential problems too as a possible valve issue meant Yamaha's customers were written to and bikes had to be returned to dealers for a free check and re-fit if necessary. The good news is the '07 models come with different valves and the changes don't end there.

The '07 bike doesn't look radically different from the '06 model - yeah there are the bold new graphics, wavey disks and Pro Taper handlebars that replace the Renthals but aside from that you'd be hard pressed to spot any change.

But the '07 is different! For starters the '07 bike's been on a bit of a diet and the Yamaha technicians have delivered a baby that's 0.7kg lighter than the '06 version. Some of the weight is lost thanks to the use of magnesium crankcase covers and a new smaller oil tank reduces engine oil capacity by 100ml which saves a little more. Even the engine guards are lighter.

The rest of the weight is saved in the chassis and running gear departments - a new more compact front brake, lighter wavey brake discs, a lighter rear shock, lightweight front fork outer tubes and new triple clamps all help make the YZF a light bike. How light? Lighter than some manufacturers' 125 two-stroke models and only 700gm heavier than the lightest four-stroke in the MX2 class - that's Suzuki's RM-Z!

And it's not just weight saving that the Yamaha technicians have worked on as the engine is modified too. New jetting as well as optimised intake, exhaust and ignition settings - whatever that means - are claimed to both clean up the running and produce more ponies.

Of course it's all very well claiming that this is better and that's better but it's on the track where it really counts. Unlike most new bike tests which are carried out over the duration of a single day at one track, our tenacious tester - tiny Tony t'Marshall - had three weeks to fully put the '07 YZF through its paces on a variety of tracks, both hardpack and sand, over the Christmas period.

But despite Britain enjoying mostly dry weather over the festive season the one day we pencil in to drive five hours to shoot Tony and the YZF in action it decides to rain. In fact it rains so hard our chosen Johnny Douglas Hamilton-built track not only floods but the driving rain kills a pair of Canon camera bodies - and our photographer's will to live - before the day's done. Bugger!

So with excuse for crap pictures made it's time to hand things over to Tony - go to it tiger!

"The first thing I noticed when I sat on the bike is that if feels high. Sutty tells me the YZF has one of the tallest seats of all this year's bikes and to me when I'm on the YZF it feels like I'm sitting on a wall because the seat feels so flat and square. I'm not sure if it's the height of the seat which makes the bars feel low or if the Pro Tapers are a low-bend bar - either way I'd prefer something a little bit higher on there.

"Also when sitting on the bike in the pits I thought it felt quite heavy - one of my friends described it as feeling like a lump when he sat on it. Luckily, out on the track that feeling of heaviness is forgotten and the YZF is a bike that handles well with the suspension feeling very well balanced.

"That feeling of balance is lost in fast bermed corners though and to me it feels like either the front is too low or the rear is sitting too high. To combat this feeling I found sitting a little bit further back on the seat through the turns helped things feel much better. That's the only place I can fault the handling of the bike as generally it's spot on.

"Yamaha 250Fs are known for having strong motors but the '07 we tested has a couple of flaws. The first was the jetting - the motor runs clean from the bottom but goes fluffy in the middle. When you clear that fluffy stage it cleans up again but the power tailed off at the top-end. I really can't decide if it's running too lean or too rich.

"What I've learnt from talking to other owners of '07 YZFs is that once the jetting is sorted it's a much improved motor over the '06 model - plenty fast and with improved over-rev.

"The other problem I encountered was shifting gear from third to fourth - it just doesn't want to do it under load. This is possibly because the bike's barely run in and it might get better with time but as it stands at the moment unless you flick the clutch in or let the gas off momentarily you're just never gonna get fourth gear. Once in fourth gear there appears to be a flat spot - hopefully this won't be there once the jetting is sorted.

"Everything else on this bike is good - the brakes and controls feel awesome - and to be honest new bikes are so good these days that the faults I've mentioned are more about me being picky than major problems.

"Overall I'm pretty impressed with the YZF250 - it does everything reasonably well and turns so much better than last year's bike. It might not be my favourite 250F of '07 but it's still a very capable bike for all levels of rider."

specifications
YZ250F

Capacity: 249cc

Bore and stroke: 77mm x 53.6mm

Transmission: Five-speed

Carburettor: Keihin FCR-MX37mm H/1

Front suspension: Kayaba fork (300mm travel)

Rear suspension: Kayaba shock (307mm travel)

Front brake: 250mm disc

Rear brake: 245mm disc

Wheelbase: 1469mm

Seat height: 997mm

Dry weight: 92.7kg