This Week in MXA, presented by O’Neal, is all about Josh Mosiman’s quest for success at the 2026 Fox Raceway, Hangtown, and Washougal Nationals. With access to bikes and parts from all of the major OEMs, Josh can race any 450 he wishes, but the selection process this year has come down to two. In the past, he has ridden different bikes at each round, but this year we’re looking for one consistent steed to ride for three planned events. Cameron Purcynski joined for the day to offer his advice and input after watching Josh on both bikes. Also, special thanks to Josh Holley for filming this video!
The battle between the Yamaha YZ450F and the KTM 450SX-F Factory Edition represents the absolute pinnacle of four-stroke motocross performance. While both are championship-winning machines, they deliver that performance through fundamentally different engineering philosophies.
🛠️ Technical Specifications & Overview
🚀 1. Engine Character & Wireless Tuning
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Yamaha YZ450F: Features a unique rearward-slanted cylinder design that creates an incredibly explosive, hard-hitting, and instantaneous throttle response. Yamaha’s biggest advantage is the GYTR Power Tuner App, which allows you to completely map fuel delivery and ignition timing via your smartphone for free.
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KTM 450SX-F Factory Edition: Delivers an exceptionally smooth, linear powerband that rolls on gently at the bottom but boasts immense, endless torque through the mid-to-top end. It features an advanced handlebar switch managing dual engine maps, Traction Control, Launch Control, and a Quickshifter for seamless, clutchless upshifts.
🏁 2. Suspension, Chassis & Handling
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Yamaha YZ450F: Widely praised for its KYB SSS coil-spring forks, which offer unmatched comfort, plushness, and high-speed stability right out of the box. The aluminum chassis makes the bike feel firmly planted and incredibly secure down rough, high-speed straights.
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KTM Factory Edition: Upgrades the standard model with premium WP XACT air suspension dialed in for aggressive racing. The lightweight chromoly steel frame offers a distinct engineered flex that makes the KTM exceptionally intuitive, nimble, and sharp when diving into tight inside corners.
💎 3. Premium Factory Upgrades
While the Yamaha YZ450F comes as a standard production bike, the KTM Factory Edition is a limited-run machine loaded with elite team-replica parts directly from the showroom floor, including:
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A vibrant orange KTM Factory Racing powder-coated frame and team graphics.
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A premium performance Akrapovič slip-on exhaust.
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Upgraded Factory wheels with CNC-machined orange hubs.
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A heavy-duty Hinson clutch cover, a composite skid plate, and a front fork holeshot device for race starts.
🎯 The Verdict: Which is right for you?
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Choose the Yamaha YZ450F if: You want a punchy, ultra-responsive engine, swear by the plug-and-play consistency of traditional spring suspension, love wireless smartphone tuning, and prioritize high-speed stability.
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Choose the KTM 450SX-F Factory Edition if: You want an ultra-lightweight bike loaded with premium, race-ready aftermarket components, prefer a smooth but endlessly pulling power delivery, and want razor-sharp cornering capabilities.
