🛠️ TRX400EX / 400X 440cc Big Bore Top End Rebuild Kit – Stage 3 Hotcam + 89mm Piston

Unleash true race power from your Honda 400EX, 400X, or XR400R with this complete 440cc big bore top end rebuild kit. Featuring an 89mm forged piston, Stage 3 Hotcam, and HD cam chain, this high-compression setup is ideal for built motors running race gas only.

Everything is brand new in original packaging. No head or case mods required.

✅ What’s Included:

• New 89mm Cylinder

• Wiseco or JE 12.5:1 Forged Piston (Race Gas Only)

• Nitrite-Coated High Temp Piston Rings

• Chrome Wristpin & Circlips

• Stage 3 Hotcam Camshaft

• Cam Bearings (x2)

• Maxlock Head Stud Kit (Lifetime Warranty)

• Cometic MLS Big Bore Head Gasket

• Complete Top End Gasket Kit (head, base, exhaust, chain tensioner)

• Heavy-Duty Timing Chain

• NGK Spark Plug

• Stickers

📦 Fitment:

Fits all:

• Honda TRX400EX (1999–2008)

• Honda TRX400X (2009, 2012–2014)

• Honda XR400R (1996–2004)

🛡️ Warranty Info:

Includes 1-year warranty on all components and lifetime warranty on Maxlock studs.
⚠️ Not DIY – must be installed by a qualified, experienced engine builder. Warranty is void for failures due to improper install, tuning, break-in, or misuse. All warranty claims require return of affected parts for inspection.