WHAT IS IT? Dick’s Racing progressively bores out the stock KTM 250SX two-stroke carb from 36mm to 39mm and installs the creative Intelajet system. It fits on all KTM two-stroke carbs from 2004 to 2012.
WHAT’S IT COST? $425.00 (carb bored progressively from 36mm to 39mm with Intelajet installed); $30.00 (Intelajet mounting kit); $40.00 (taper-bore carb ends).
CONTACT? www.dicksracing.com or (916) 722-2373.
WHAT STANDS OUT? Here’s a list of things that stand out with Dick’s Racing 36mm to 39mm carb mod.
(1) Stock KTM carb . Believe it or not, KTM mounts small 36mm Keihin PWK carbs on their 250cc and 300cc two-strokes. Most two-strokes come with 38mm or larger carbs.
(2) Dick’s Racing carb. Dick Wilk taper-bores the stock KTM carb so that it flows from 36mm to 39mm; he can also taper-bore the ends for even more power. Tapering the carb’s bore makes the Keihin PWK work like a 36mm carb below one-third throttle but a big carb above that.
(3) 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 main jet. It has the feel of a supercharger. The Intelajet doesn’t dump raw fuel into the carb as much as it sprays a fine mist into the air stream to enhance fuel burn at high rpm. The amount of fuel coming through the emulsion tube is controlled by an air-bleed dial, which is accessible to the rider.
(4) Jetting. The only jetting change that we made to our preferred 2012 KTM 250SX brass was to replace our 160 mainjet with a smaller 152, because the Intelajet emulsion tube spray makes up for any loss in high-rpm fuel.
(5) Performance . Awesome! Incredible! Worth the money! Amazing! Fantastic! Unbelievable! Pick the adjective that you like best. The gain in top-end power and overrev was immediately noticeable to every MXA test rider. It has no effect on power below two-thirds throttle, but once the mist kicks in, the KTM 250SX feels like it has a jet pack attached to it.
WHAT’S THE SQUAWK? We had to fiddle with the needle clip and air screw to keep the midrange tuned to the high-rpm overdrive, but it was not a big deal.
In three words: we love it.