Honda 400EX Engines and Parts | Rebuild Kits
Get your 400 EX sport quad back on the dunes, trail, or track with precision rebuilt components. Search by model year breakdown to find exact-fit solutions for your air-cooled 397cc machine.
We supply full rebuild solutions organized across all Honda TRX400EX and TRX400X model years:
- First Generation TRX400EX (1999–2004): Kick-start and electric-start top/bottom end overhaul kits, standard and big-bore cylinders, crankshafts, and gasket sets
- Second Generation TRX400EX with Reverse (2005–2008): Complete remanufactured air-cooled engines, master rebuild packages, reverse-gear transmission parts, and piston kits
- TRX400X Series (2009 & 2012–2014): Direct-fit replacement engine assemblies, forged performance pistons, heavy-duty crank assemblies, and gasket kits
- Cylinder Heads & Valvetrain: Reconditioned RFVC cylinder heads, valves, heavy-duty rocker arms, camshafts, and timing chain kits
Fast Core Returns & 1-Year Warranty
Send us your core with our fast nationwide 2-way shipping. Every engine and part includes our 1-Year No-Fault Warranty. Built for dealers, shops, DIY mechanics, and riders.
