Yamaha YZ250F

Yamaha’s YZ250F is nearly 10 years old. It’s a difficult age, especially for a child prodigy like the YZ-F. You see, when it was born there was no other like it and so there was an awful lot of attention on the little thumper.

Add to that the fact it’s bigger brother was wiping the floor the world over, and you can see how expectations could’ve become too much for the new quarter-litre machine. However, it didn’t just meet those expectations – it blew them away.

There’s a fair debate that could be started on the EFI versus carby issue, which we’ll save for another time. Yamaha has bucked the trend that Honda and Suzuki have embraced and insisted that after countless hours of testing it simply couldn’t find an advantage in EFI over a carburettor. That’s a big call given that some of the competition promote EFI as a major selling point.

A quick look over the YZ250F shows that even if EFI was present, it would only represent the tip of the iceberg as far as changes go for 2010, as the new model has been reworked from end to end.

The all-new bilateral beam frame is more rigid and compact than the previous perimeter frame, and Yamaha has used this as the starting point in its quest for improved handling.

The updated frame design also gave the opportunity to tinker with other areas, resulting in a new sub-frame, a repositioned radiator, a smaller oil tank, new engine brackets and a new airbox intake.

The YZ’s engine has also received plenty of attention, and Yamaha states it was specifically built to match the frame’s characteristics, instead of tackling things from the other way around.

Changes were made to the carburettor and ignition timing, while a new exhaust was also fitted. The clutch spring load was increased and new ratios were worked for third and fourth gear. The intake cam timing remains the same but the cam profile of has been raised by 0.1mm.

The suspension department seems to have been the quietest, with only relatively minor changes to both ends, but it was hard to complain about the ’09 model’s springs anyway, so we can understand that. However, Yamaha did make changes to the fork’s inner rods and damping settings, and it increased the rigidity of the outer tubes. The shock was repositioned lower in the frame and scored new damping rates. And it’s blue.

So now we get to the shallow part – its looks. Well the pictures don’t do it complete justice and I’ll put my hand up here and say I’ve bagged Yamaha for a few years about how tired its bikes are looking. The YZ250F, however, is a stunner. It looks fast just sitting on the stand and it’s just as sweet on the track. It makes you want to ride it. And if the brand new plastics and graphics aren’t enough then the knowledge that the clutch is now a whole three per cent lighter will surely be the deal clincher.

Jamie knows the YZ like the back of his Axo glove. He races one in A grade and also works as a mechanic for both the busy B&C Motorcycles at Boolaroo, NSW (thanks for letting him out for the day, Brad), and also the Rad MX motocross team.

After acclimatising to the slight change in ergos from the 2009 YZ, Jamie hit the Cessnock motocross track to get to grips with the 2010 machine.

The first notable difference was not in fact the handling but the engine. Jamie was able to hold gears much longer and the spread of power throughout the rev range was obviously superior to the older model.

Given these were new bikes we were testing the suspension was understandably a bit stiff – this was giving Jamie some grief, particularly in the whoops. After swinging by the pits a couple of times for some fine tuning, the YZ started to settle and the lap times came down. From there on Jamie said it was impossible to find any major fault with the YZ.

He reckons it’s a better bike than last year in just about every way, which is a big call but a view shared by pro rider Mitch Hoad, who was also on hand during the test day.

Power-wise the 2009 has a stronger midrange and top end [than previous models]. Much stronger. At the bottom Jamie found a slight hesitation that was alleviated in part by turning the air screw out one-and-a-half turns, but as we found in the bush, it was at higher revs that the YZ shone.

However, the talking point on the track, as it was on the trails, was the outstanding suspension. At standard settings it didn’t feel too rigid and the YZ’s ability to track through corners and remain stable was impressive.

– Damien Ashenhurst

Changes 
2009 model -