One major handling mod that we went for was the Renthal Twinwall handlebar in the Windham bend, which gave us 12mm more height than the low-feeling stock bar, plus the added strength of a crossbar. We also popped on a Twin Air PowerFlow Kit, which can only be described as an essential modification for modern KTMs. The stock filter is difficult to get seated against the airboot and can leak unwanted dirt and debris, while the PowerFlow Kit replaces the stock cage with a unit that seats firmly and perfectly against the seal. The result is an easier-to-change air filter system that performed flawlessly and doesn't let a speck of dirt in. No doubt, this was one of the big contributing factors to the 350 XC-F making it all year with zero major issues.At approximately 30 hours we checked the valves on the 350 and found that everything was in spec. Following this, the bike was entered in the Glen Helen 12-Hour with January guest editor Ricky Johnson, Andrew Wilkins, Michael Gaynor and myself jamming the bike around the dusty Glen Helen course for a half day's worth of pure fun. The weather was hot and the track became super rough, yet the KTM kept purring the entire time. The clear 2.5-gallon fuel tank was hugely appreciated during pit stops, and the clutch on the bike showed no signs of wear even with a few tight canyons on the upper portion of the racecourse. The suspension, however, was entirely too soft for the weights and speeds we were throwing at it, and at this point the setup was feeling a bit sloppy. Next stop? Pro Circuit.