Hang ’em high: KTM’s unique nylon silencer mount is virtually
bulletproof. Of course, the 250SX is two-meter-max legal.
MXA KTM 250SX
SETUP SPECS This is how we set our KTM 250SX up for racing. We offer it as a guide to help you find your own sweet spot.
WP FORK SETTINGS For hardcore racing, we ran this setup on the 2012 KTM 250SX (stock specs are in parentheses). Spring rate: 0.46 kg/mm Oil height: 370cc (380cc) Compression: 7 clicks out ( 12 out) Rebound: 12 clicks out Fork-leg height: 5mm up (flush on a sandy track) Notes: The cheapest way to fine-tune the KTM’s WP forks is to raise and lower the fork-oil height to get the smoothest midstroke action without bottoming, which is why we lowered the oil height by 10cc. KTM’s forks come with different oil heights for each model. The 125SX and 150SX have their oil set at 360cc, the 250SX has 380cc, and the four-strokes roll out of the factory with 390cc.
WP SHOCK SETTINGS For hardcore racing, we ran this setup on the 2013 KTM 250SX (stock specs are in parentheses). Spring rate: 5. 4 kg/mm Race sag: 105mm Hi-compression: 2 turns out Lo-compression: 15 clicks out Rebound: 12 clicks out Notes: We ran a 1.25mm-longer Pro Circuit shock linkage. Not only did it lower the rear of the bike by 10mm, but it stiffened up the initial part of the shock’s stroke to help widen the range of the stock 5. 4 shock spring. Faster or heavier riders might be required to go to the stiffer 5. 7 kg/mm shock spring. If you are savvy, you will use free sag to make the decision for you.
KEIHIN PWK JETTING SPECS Here are MXA’s recommended jetting specs for the 36mm Keihin PWK carb (when changed, stock specs are in parentheses). Mainjet: 158 Pilot: 40 ( 42) Needle: N1EH needle (N1EI) Clip: 4th clip from top (3rd) Air screw: 1-1/2 turns Notes: For the full-race effect, we sent our carb off to Dick’s Racing to have it taper-bored to 39mm with an Intelajet system installed. This mod boosts the top-end power significantly. For more info, go to www.dicksracing.com.
( 4) Torx bolts. It took us a decade to get KTM to stop using Allen bolts and switch to 8mm and 10mm hex heads. Then, once KTM had become mainstream, they decided to switch to Torx. We assume that Whitworth was already taken. They have mitigated their hubris by including a Torx wrench in the tool kit and making the engine-case bolts accept both Torx and hex head wrenches. Q: WHAT DID WE LIKE? A: The like list: (1) Price. Expect to spend close to $1800 less for a 250SX than a 450SXF. That money could finance your complete racing season, plus you can do the maintenance yourself with little more than a nutcracker and a butter knife; the savings will be magnified by the lower cost of maintaining a two-stroke. ( 2) Cosmetics. You can’t make everyone happy with your proprietary look, but KTM has done a good job of blending modern-design aesthetics with functionality. ( 3) Weight. We could act happy that the 2013 KTM 250SX weighs only 218 pounds, but we remember when it weighed 212 pounds. We can feel the extra 6 pounds—and we are surprised that KTM’s test riders can’t. Four-strokes are bloated and fat; two-strokes shouldn’t be. ( 4) Brakes. They are awesome on KTM’s 243-pound four-stroke, so imagine how good they are on a bike that is 25 pounds lighter. ( 5) Fender. Everybody has to have a hobby. For KTM’s engineers, it is designing the most overblown front fenders in the biz. Don’t they ever ask themselves how Honda, Yamaha, Suzuki and Kawasaki can make a small, light and normal-looking fender? They should, because the I-beam front fender is too much—too much plastic, too much weight, too much thought. On the other hand, it is better than what they had before. ( 6) Hydraulic clutch. Don’t Honda, Yamaha, Suzuki and Kawasaki ever ask themselves why they have iffy clutches when KTM has the best clutch made? ( 7) Thread-on gas cap. We asked for it. Q: WHAT DO WE REALLY THINK? A: If you’re in the market for a new bike in 2013, you owe it to yourself to put the KTM 250SX two-stroke on your short list. It’s lighter, cheaper, easier to maintain, snappier, better handling, quicker stopping and makes more horsepower per cc than any four-stroke— short of the one in John Force’s work car. ;