WHAT IS IT? The Pro Circuit Works pipe gives the KTM 250SX smoker more of what it needs without harming anything it already has.
WHAT’S IT COST? $249.95 (raw metal or chrome pipe), $329.95 (carbon fiber silencer), $134.95 (aluminum silencer).
CONTACT? www.procircuit.com or (951) 738-8050.
WHAT STANDS OUT? Here’s a list of things that stand out with the Pro Circuit 2017 KTM 250SX pipe and R-304 silencer.
(1) Fitment. All the OEM KTM hardware transferred over to the Pro Circuit pipe and silencer. There are two things you need to do before installing the pipe. First, move the stock O-ring out of the OEM pipe and insert it into the Pro Circuit pipe. Second, the silencer needs the rubber grommets and aluminum spacers from the stock KTM silencer transferred over. Be careful not to lose any parts of the two-piece spacers; they have a tendency to fall out. The pipe fits perfectly.
(2) Silencer. If you are short on cash and want the most bang for your buck, just get the R-304 muffler. For some reason, since way back when Jeremy McGrath was at KTM in 2002, the Pro Circuit silencer has been magic with the stock pipe. It hits hard, pulls harder and revs further. Since you are a penny-pincher, we doubt that you will spend $330 on Pro Circuit’s carbon fiber muffler, but if you do, be forewarned that carbon canisters have a finite lifespan that is one-tenth that of an aluminum canister.
(3) Performance. Every MXA test rider loved the 2017 KTM 250SX powerband; but, if given the opportunity to tune it to our tastes, we would want more top-end power and some added over-rev. The stock pipe delivers incredible midrange but falls off quickly after its peak at 8200 rpm where it was making 47.30 horsepower. With the Pro Circuit Works pipe installed, peak is moved to 49.60 horsepower at 8300 rpm. That is a 2.2-horsepower gain at peak, but most important, the pipe didn’t fall off as quickly after peak as the stocker. The Pro Circuit pipe made the same power as the stock pipe from 5000 rpm all the way to 7200, then the Pro Circuit pipe made 1 horse more at 7500 rpm, 1.6 more at 8000 rpm and 4 horses more at 9000 rpm. Best of all, it kept all the good traits of the KTM 250SX and just added more power after 7200 rpm.
(4) Jetting. We increased the main jet from a 440 to a 450, which means you might have to go richer in cold weather. We also turned the air screw out 3-1/2 turns, which points towards a leaner pilot jet. We made these mods for the stock KTM pipe, and they worked well with the Pro Circuit pipe.
WHAT’S THE SQUAWK? No complaints.
MXA RATING: If you’re in the market for a 2017 KTM 250SX, you are going to want this pipe and silencer to fill in the upper half of the powerband. Good stuff.
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