TRX 400EX 400X 87mm Big Bore Cylinder +2mm Top End Rebuild Kit Complete Assembly

🔥 TRX400EX / 400X 87MM +2MM BIG BORE REBUILD KIT

Complete Top End Assembly – Fits All Honda 400EX, 400X, XR400 Models

If you're rebuilding your Honda 400 and want more power, more durability, and the peace of mind of a full warranty, this is the most complete, high-quality kit on the market — period.

We've sold thousands of these TRX400EX rebuild kits across all sizes — 85mm, 86mm, 87mm, 88mm, 89mm — and we proudly stand behind every one. Your kit includes everything needed for a high-performance, no-compromise top end build with a 1-year warranty and lifetime tech support.

Kit Includes:

- BPRATV 87mm Nikasil Big Bore Cylinder (1 Year Warranty)
- Wiseco, JE, CP Carrillo, or Wossner Forged Piston*
- High-temp piston rings
- Wrist pin and circlips
- Talon Titanium Head Stud Kit (Lifetime Warranty)*
- Cometic Big Bore MLS Top End Gasket Kit
- Heavy Duty Timing Chain
- Full 1-Year Warranty on Entire Kit*

Fits the Following Models:

- TRX 400EX (All Years)
- TRX 400X (All Years)
- XR400 (All Years)

⭐️ Why Buy from BPRATV?

BPRATV – The Best Parts. The Best Performance. The Best Price.

BRAPPPPPPPPPP!

No one supports 400EX owners better than we do. Trusted by builders, riders, racers — and backed by real warranty & tech help.

⚙️ Build it Right the First Time

Better performance, stronger parts, no cut corners. This kit delivers everything.

❓ Frequently Asked Questions

Q: Will this work on my 2003 TRX400EX?
A: Yes — this kit fits all years and models of TRX 400EX, TRX 400X, and XR400.

Q: Do I need to modify anything?
A: No — the kit is drop-in ready with OEM-fit components. Tuning recommended.

Q: Which piston brand comes with the kit?
A: We include a top-tier forged piston from Wiseco, JE, Wossner, or CP — depending on current availability.