Pro Circuit KTM 65 SX Project Bike - Dirt Rider Magazine

When Pro Circuit called recently saying that they had a KTM 65 SX project bike for us to test, we just knew that Mitch Payton and the boys had cooked up something magical. With plenty of experience tuning two-strokes and huge amounts of time, money and effort dedicated to pumping up the mini race scene, Pro Circuit never fails to delivery in the performance department. After grabbing the bike and DR test rider Derek Drake, we hit the track to see what we could learn about the KTM.

Probably the biggest feature of the modified 65 SX is the motor. PC kept it simple and sweet with some careful head and cylinder modifications helped the bike achieve peak power. Additional horsepower gains were found through the easy installation of a Works Pipe, capped off by an R-304 silencer. The big-news mod here is the Adjustable Power Valve that essentially allows dad to adjust the power curve to junior's preferences. The unit comes pre-set from Pro Circuit with what they feel are the best settings, but ultimately it's up to the end user to determine what kind of character they want the motor to have.

On the track, our 70 lb. test rider took little time in getting used to the PC bike. The little KTM flew around the track with the usual velocity of a modified mini, except in this case the bike was clearly staying hooked up to every square inch of dirt that the knobbies came in contact with. Pro Circuit dialed this machine in to operate on useable acceleration and crisp delivery (rather than sheer, arm-ripping power), and the outcome was a bike that Derek could carry plenty of momentum on without having to worry about the power dropping out.

Handling-wise, a number of significant changes were made by PC in order to fine-tune the machine for the rigors of amateur national racing. Pro Circuit spared no expense in throwing DLC coating and aftermarket valving at the KTM's fork and shock, along with a Bladder Cap Kit, trick anodizing and fresh fluid. The sum of these changes is a suspension setup that better resists heating under race conditions while providing better action, increased bottoming resistance and improved rider feel. Basically, they took all of the KTM's stock suspension strong points and amplified them by ten.All together, the Pro Circuit KTM 65 SX is an insane little motorcycle with huge potential for racing applications. To see more about this machine-including expanded opinions from Derek Drake and a complete parts list-check out the November issue of Dirt Rider, and head on over to to see what kind of magic the boys at PC can work for you!