Honda TRX400EX / TRX400X 440cc Big Bore Top End Rebuild Kit – 89mm +4mm Stroker

🛠️ Upgrade your Honda 400EX or 400X with this complete 440cc big bore top end kit. Designed to deliver serious performance gains without case or head mods, this kit combines premium components including a forged piston, Stage 2 Hotcam, titanium stud kit, and hardened valves for reliable, pump gas-friendly power.

✅ What’s Included:

• 89mm Nikasil-plated cylinder

• 89mm Wiseco or Wossner forged piston

• High-temp piston rings

• Chrome wristpin & circlips

• Cometic top end gasket kit

• Hotcams Stage 2 performance camshaft

• Camshaft bearings

• Talon Grade 5 Titanium cylinder head stud kit

• Heavy-duty timing chain

• Hardened steel intake & exhaust valves

• Valve springs and retainers

• Viton valve stem seals

• Stickers

📦 Fitment:

Fits all Honda 400EX (1999–2008) and TRX400X (2009–2014) models.
No case or head modifications required.

🛡️ Warranty Info:

Covered by a 6-month limited warranty. Warranty covers defects in materials and workmanship. Professional installation recommended for best results.