( 18) EXHAUST PIPE In stock trim, the KTM 250SX makes the most horse- power of any 250cc two-stroke sold. It peaks at an amazing 50 horsepower at 8400 rpm. If the 2013 KTM has a weak link, it is that the power doesn’t do much after peak—and, in fact, drops off to 44 horsepower by 9000 rpm. Bolting on a Pro Circuit 250SX pipe kicked it into overdrive. At 8500 rpm, it made 1/2 horse more. At 9000 rpm, the Pro Circuit pipe made 5-1/4 horsepower over the stocker, and at 9500 rpm, it made an amazing 7 horses more. Those extra horses on the high end of the rpm scale are the meat on the bones of the 2013 powerband. ( 19) SILENCER Although we ran the Pro Circuit pipe and R304 silencer together, we also wanted to see what the Pro Circuit silencer would do when mated to the stock KTM exhaust system. Surprise! The R304 silencer pumped peak horse- power up to 51 ponies and added 2 horses to the powerband from 8600 rpm to 10,000 rpm. If you can’t afford the Pro Circuit pipe and silencer combo, just buy the R304 silencer. It’s that good. ( 20) SUBFRAME We think the KTM 250SX is too tall. The best solution is to cut the subframe down. Luckily, a KTM sub- frame is the easiest one to lower. We remove the subframe and weld up the lower subframe bolt hole. Then we drill a new hole 5mm higher (and countersink it for the bolt). The final step is to trim the excess material off the bottom of the subframe. Don’t get carried away; lower- ing the subframe by 5mm at the bolt holes will lower the rear almost an inch. ; ( 15) INTELAJET What is Intelajet? It is the two-stroke equivalent of the dual fuel-injection nozzles on the 2012 Kawasaki KX250F. The Keihin carb functions normally below two-thirds throttle, but as air velocity increases, excess fuel is sprayed out of the Intelajet’s emulsion-tube upstream from the mainjet. It feels like a supercharger. The amount of fuel coming through the emulsion tube is controlled by an air-bleed dial that is accessible to the rider. The performance is awesome! Every MXA test rider immediately noticed the gain in top-end power and overrev. It has no effect on power below two-thirds throttle, but at high rpm, it feels like it has a jet pack attached to it. The retail price is $425 (carb bored progressively from 36mm to 39mm with Intelajet installed), $30 (Intelajet mounting kit) and $40 (taper-bore carb ends). For more information, go to www.dicksracing.com or (916) 722-2373. ( 16) 7602 BRAKE PEDAL TIP Many MXA test riders wish that the KTM brake-pedal tip was easier to reach and a little longer. Colorado- based 7602 Racing offers a 7075 aluminum brake tip that slips right onto the stock KTM mounting holes. Plus, it has more aggressive teeth. For more information, go to www.7602racing.com or call (719) 274-0606. ( 17) AIR FILTER Never assume that you have gotten the KTM’s filter in the proper place. MXA test riders have learned through experience (the bad kind) to reach behind the filter to make sure that it is flush with the airbox. We have seen riders put air filters in their bikes upside down without realizing it. Be careful; the life of your top end depends on it.
20 WAYS TO MAKE YOUR 2013
KTM 250SX BETTER