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Due to Thanksgiving and the holiday rush, our current handling time is approximately 4–5 business days. We sincerely appreciate your patience and understanding. We truly appreciate your business and are thankful for another great year serving our customers. If you have any questions or concerns, please contact us—our team is working as hard as possible to ship all orders promptly.
Due to Thanksgiving and the holiday rush, our current handling time is approximately 4–5 business days. We sincerely appreciate your patience and understanding. We truly appreciate your business and are thankful for another great year serving our customers. If you have any questions or concerns, please contact us—our team is working as hard as possible to ship all orders promptly.

TRX400EX TRX 400EX 400X 88mm Big Bore Cylinder 426cc Top End Engine Rebuild Kit

by BPRATV
Sold out
Original price $486.10
Original price $486.10 - Original price $486.10
Original price $486.10
Current price $388.88
$388.88 - $388.88
Current price $388.88

12100-KCY-670, 12191-KCY-672, 13011-KCY-670, 13101-KCY-670, 90601-KA5-000, 13111-KCY-670, 12100-HN1-A70, 12191-KCY-672, 12251-HN1-003, 12391-KCY-671, 14560-KCW-851, 12100-HN1-A70, 12191-KCY-672, 13011-KCY-670, 12100-KCY-670, 4606M08800, C7826, 71016-4, 12191-KCY-673, 13011-KCY-670, 90601-KA5-000, 13103-KCY-670,13111-KCY-670, 12251-HN1-003, 12209-KL4-005, 4040, 4606M08700, 4606M08800, 4667M08900, 808829, 808894, 8604DA, H0402027S, M2033

Honda TRX 400EX/X & XR400R 88mm Big Bore Cylinder Kit – Complete 426cc Top-End Rebuild with Premium Performance Parts


Maximize your Honda 400EX, 400X, or XR400R’s performance with the 88mm Big Bore Cylinder Kit – 426cc Top-End Rebuild, the ultimate upgrade for power-hungry riders. Precision-engineered for all models and years, this complete kit delivers unmatched reliability, durability, and aggressive performance gains without any case or head modifications.

What’s Included in the Kit?

  • 88mm heavy-duty big bore cylinder: Built to last under extreme conditions.
  • Premium forged piston kit (Wiseco or Wossner): Lightweight, high-strength performance for superior combustion.
  • Nitrite-coated piston rings, chrome wrist pin & circlips: Reliable sealing and durability.
  • Cometic big bore gasket kit: Comprehensive seal for maximum efficiency, including an MLS head gasket.
  • Talon TITANIUM cylinder head stud kit: Backed by a lifetime warranty, built to handle extreme pressure.
  • BPRATV heavy-duty cam chain: A perfect match for your high-performance build.

Key Features You'll Love:

Power & Versatility: Boost your engine’s displacement to an impressive 426cc. Runs flawlessly on both pump gas and race fuel.
DIY-Friendly: No need for case or head modifications – hassle-free installation.
Rider Confidence: Durable, high-quality components backed by a 1-Year Warranty for your peace of mind.
Proven Performance: Engineered by BPRATV, your go-to for the best parts, unbeatable performance, and incredible value.

Experience the adrenaline-pumping advantage of a high-performance 426cc engine on your next ride. Whether you’re shredding dunes or hitting the trails, this kit ensures your ATV dominates with power, reliability, and excitement.

Upgrade Today! BPRATV – The Best Parts. The Best Performance. The Best Price. BRAPPPP!

12100-KCY-670, 12191-KCY-672, 13011-KCY-670, 13101-KCY-670, 90601-KA5-000, 13111-KCY-670, 12100-HN1-A70, 12191-KCY-672, 12251-HN1-003, 12391-KCY-671, 14560-KCW-851, 12100-HN1-A70, 12191-KCY-672, 13011-KCY-670, 12100-KCY-670, 4606M08800, C7826, 71016-4, 12191-KCY-673, 13011-KCY-670, 90601-KA5-000, 13103-KCY-670,13111-KCY-670, 12251-HN1-003, 12209-KL4-005, 4040, 4606M08700, 4606M08800, 4667M08900, 808829, 808894, 8604DA, H0402027S, M2033

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