When it comes to two-stroke motocross bikes, there’s obviously a lack of manufacturers who continue to develop or even produce these models. The four-strokes may have taken over professional racing, but the premix machines definitely have their place in the sport and KTM can see that. So for 2017 KTM decided to completely overhaul their 250 SX and the amount of work put into the model is quite impressive.

Obviously the most noticeable difference right away is the updated bodywork and ergos. For 2017 the KTM 250 SX now features the latest bodywork shape and graphics to bring it in line with the rest of the two and four-stroke range. This is great to see and will definitely put a smile on two-stroke fan’s faces around the country.

The 2017 KTM 250 SX features a lightweight chrome-moly steel frame designed to improve handling, rideability, cornering and stability. The frame also features high torsional rigidity and low longitudinal stiffness, this results in better absorption of the energy created from the front and rear suspension, sucking up jumps and bumps.

Image: Alex Gobert (Foremost Media).

Creating the lightest and slimmest 250 SX to date, KTM engineers were able to shave one kilogram off the frame for 2017 thanks to features such as a sub-frame that weighs in at less than 900g. The 2017 KTM 250 SX also features a lightweight single-component cast aluminium swing-arm to eliminate inconsistencies and weak points from welding – it also looks great too!

Obviously another huge update for 2017 in both the performance and weight departments is the addition of the new WP AER 48 fork. Making the switch to the air fork for 2017 was a big move across the board for KTM, but it was definitely the right move. This updated chassis and suspension package is very impressive, it’s a totally different machine.

The ability to adjust the air fork to suit your needs within minutes is a massive advantage. Obviously you need to know what you’re doing, but if you can work it all out, you’ll definitely be able to get your bike feeling exactly how you’d like it to feel. Luckily for us we had KTM Australia’s Danny Apro on hand to massage the 2017 KTM 250 SX suspension settings all day.

Image: Alex Gobert (Foremost Media).

In the end I settled on a fork pressure of 9.2 bar, 16 clicks out on compression and 17 clicks out on the rebound. Paired with a rider sag of 108mm in the rear, this combination felt very balanced and allowed the bike to corner the way I wanted. Although the bike turned in and went wherever I’d like on track, it still remained stable at all times, which is definitely what you’re searching for when it comes to setting up your ride.

Now we’re obviously impressed with the chassis and suspension updates for 2017, but we’re also very impressed with the engine updates at the same time. KTM really put a lot of work into the 2017 250 SX engine and that is apparent as soon as you ride onto the track. Remember how much your old 250 two-stroke rattled and vibrated? Well, that’s a thing of the past with the 2017 KTM 250 SX.

Thanks to the new engine design, the 2017 KTM 250 SX now features a lateral counter balance shaft, which reduces vibrations by a huge 50 percent at the handlebars and footpegs. This counter balance shaft setup is a huge improvement; it’s unbelievable just how smooth this bike is for a 250 two-stroke. I feel it’s something that is actually quite hard to put into words, you really do have to ride one to see it, or should I say feel it for yourself.

Image: Alex Gobert (Foremost Media).

For 2017 KTM also improved the mass centralisation of the 250cc power plant, updated the engine cases, cylinder, transmission and carburettor. The all-new die-cast engine cases allow for the improved mass centralisation and the addition of the counter balance shaft. The cylinder also has all-new ports and features and overhauled power valve system.

In the transmission department, the 2017 KTM 250 SX features the same gear ratios as its predecessor, but this time engineers took a closer look at the mechanism. The result of this is a more precise shifting action as you move through the five-speed gearbox to ensure you’re powering around the track at all times.

Replacing the previous Keihin unit, the 2017 KTM 250 SX now features a new Mikuni TMX carburettor. This 38mm flat slide carb provides smooth and controllable power throughout the rev range and it’s also less sensitive to different altitudes and temperatures. This is a huge deal when it comes to carburettors, as we all know how much of a hassle they can be at times.

Image: Alex Gobert (Foremost Media).

Overall the 2017 KTM 250 SX engine is very impressive and very fast. It’s so smooth that is almost tricks you into thinking this thing isn’t an absolute animal, it will still bite you if you’re not careful. Yes it is unbelievably smooth for a 250 two-stroke, but you definitely do need to respect it and ride it correctly or you’ll find yourself in a tonne of trouble quite quickly.

As I said, it’s great to see KTM bring their flagship two-stroke motocross model up to date and in line with the rest of the range for 2017. Let’s also remember that the model still features the regular KTM bells and whistles such as the hydraulic clutch, Brembo brakes, black Excel rims and in-mold graphics to name a few.

This is the latest in two-stroke motocross technology and it’s a credit to KTM engineers as they continue to push their two-stroke program with this model. The 2017 KTM 250 SX is now available Australia wide at a recommended retail price of $11,495, be sure to head to your local dealer to check one out or head to www.ktm.com.au for more information.