Its DOHC, liquid-cooled engine produces plenty of power and has been dubbed a top-end monster by many test riders due to its dual fuel injection.
A second injection nozzle is located in the inlet tract before the throttle body and operates at high revs. This injector helps to deliver more fuel as well as help the atomization process.
On earlier odels with DFI you could actually feel this second injector kick in almost like a surge in the powerband but, as development progressed this, became less noticeable. The other cool feature is the Showa separate-function fork. This means that the right fork leg houses a spring with no damping chamber.
The preload can be adjusted using a nut on top of the fork, unlike conventional forks which need to be disassembled and have washers fitted or removed to adjust the preload. The other benefit of this fork is that, if you are changing your spring rate you only need to pull one leg apart.
The left hand leg houses the damping cartridge. This leg contains the adjustable compression and rebound damping like any normal closed-cartridge fork. These forks allow a large range of adjustability but do have the tendency to build up air pressure inside. This can cause the fork to feel harsh but the simple fix is to bleed the air after each ride-through the valves in the fork caps.
If you are looking into buying a second-hand KX250F take a look at the fork seals. Seal life on the SFF proved to be a problem if you used cheap seals. Cheap seals like the ones you get off E-bay tend to last one or two rides and then they leak straight away. My advice is to bite the bullet and fit SKF fork seals.
They are dearer but I have known people to get 12 months out of a set with no leaking. This turns out to be much cheaper in the long run. As usual with any modern four-stroke, make sure it starts easily hot and cold and make sure it idles smoothly.
Bikes with low compression problems due to leaking valves or piston rings will struggle to idle smoothly and will be difficult to start. The only other thing to check out is the linkage bearings. They receive very minimal grease from new and if not pulled apart and regreased periodically then it is normal for them to seize up in a matter of twelve months.
The KX is a great bike that if regularly serviced and taken care of will be a reliable and fun bike to own. Aim to change the engine oil at or before five hours of use, clean the air filter and re-oil it after every ride and have the valve clearances checked or adjusted every ten hours to keep the KX in top condition.
ADB Tech Editor: Mat Boyd
NEW
2012 $10,999
2013 $10,999
2014 $10,999
2015 $9999
SECOND HAND (redbook.com.au)
2012 $5600 – $6600
2013 $6100 – $7200
2014 $6600 – $7800
2015 $7200 – $8500
MARKET EQUIVALENT
YAMAHA YZ250F
$5900 – $8600
HONDA CRF250R
$5800 – $8700
Suzuki RM-Z250
$5300 – $7700
KTM 250 SXF
$5400 – $9000
