{"product_id":"honda-trx400ex-440cc-big-bore-kit-stage-3-hot-cam","title":"400EX 400X XR400 89m 440 Big Bore Kit Stage 3 Hotcam 1051-3 Cam Top End Redo Kit","description":"\u003cp style=\"text-align: center;\"\u003e\u003cspan style=\"font-size: 0.000000px; color: transparent;\"\u003eComplete Honda TRX400EX 440 big bore kit with 89mm cylinder, Stage 3 cam, forged piston, titanium head studs, Cometic gaskets and heavy-duty cam chain. \u003c\/span\u003e\u003c\/p\u003e\u003cdiv style=\"max-width:800px;margin:0 auto;font-family:Arial,Helvetica,sans-serif;line-height:1.5;color:#222;\"\u003e \u003ch2 style=\"text-align:center;font-size:26px;margin:0 0 12px 0;\"\u003e \u003cstrong\u003eHonda TRX400EX 400X XR400 89mm 440 Big Bore Kit Stage 3 Hot Cam Complete Top End Rebuild\u003c\/strong\u003e \u003c\/h2\u003e \u003ch3 style=\"color:#c00;margin:20px 0 6px;text-align:center;\"\u003e📖 Product Description\u003c\/h3\u003e \u003cp style=\"text-align:center;\"\u003e\u003cspan style=\"font-size:16px;\"\u003e The \u003cstrong\u003eBPRATV 89mm 440cc Big Bore Kit with Stage 3 Hot Cam\u003c\/strong\u003e is the ultimate high-performance top end rebuild for your Honda TRX400EX, TRX400X, or XR400. Designed for riders who demand brutal torque, aggressive throttle response, and race-inspired acceleration, this complete kit transforms your stock 400 into a hard-pulling 440cc powerhouse built for competition. \u003c\/span\u003e\u003c\/p\u003e \u003ch3 style=\"color:#c00;margin:20px 0 6px;text-align:center;\"\u003e🔥 Key Features \u0026amp; Complete Kit Contents\u003c\/h3\u003e \u003cp style=\"text-align:center;\"\u003e\u003cspan style=\"font-size:16px;\"\u003e This is a true \u003cstrong\u003ecomplete top end redo kit\u003c\/strong\u003e — not a partial rebuild. Every critical performance component is included so you can rebuild with confidence using premium parts from \u003cstrong\u003eBPRATV, Wiseco, Wossner, JE, CP, Cometic, SKF, NGK, Hot Cams, and Maxlock\u003c\/strong\u003e. \u003c\/span\u003e\u003c\/p\u003e \u003cul\u003e \u003cli\u003e\u003cspan style=\"font-size:16px;\"\u003e\u003cstrong\u003eBPRATV 89mm aftermarket big bore cylinder\u003c\/strong\u003e (440cc conversion)\u003c\/span\u003e\u003c\/li\u003e \u003cli\u003e\u003cspan style=\"font-size:16px;\"\u003e\u003cstrong\u003eForged piston kit\u003c\/strong\u003e (Wiseco, Wossner, JE, or CP based on availability) with high-temp rings, chrome wristpin \u0026amp; circlips\u003c\/span\u003e\u003c\/li\u003e \u003cli\u003e\u003cspan style=\"font-size:16px;\"\u003e\u003cstrong\u003eCometic complete top end gasket kit\u003c\/strong\u003e\u003c\/span\u003e\u003c\/li\u003e \u003cli\u003e\u003cspan style=\"font-size:16px;\"\u003e\u003cstrong\u003eCometic MLS 89mm big bore head gasket\u003c\/strong\u003e\u003c\/span\u003e\u003c\/li\u003e \u003cli\u003e\u003cspan style=\"font-size:16px;\"\u003e\u003cstrong\u003eHot Cams Stage 3 camshaft\u003c\/strong\u003e for aggressive mid-to-top end gains\u003c\/span\u003e\u003c\/li\u003e \u003cli\u003e\u003cspan style=\"font-size:16px;\"\u003e\u003cstrong\u003eBPRATV Talon Heavy Duty cam chain\u003c\/strong\u003e (thicker \u0026amp; wider than OEM)\u003c\/span\u003e\u003c\/li\u003e \u003cli\u003e\u003cspan style=\"font-size:16px;\"\u003e\u003cstrong\u003eSKF cam bearings\u003c\/strong\u003e (both included)\u003c\/span\u003e\u003c\/li\u003e \u003cli\u003e\u003cspan style=\"font-size:16px;\"\u003e\u003cstrong\u003eMaxlock Titanium head stud kit\u003c\/strong\u003e – Lifetime Warranty\u003c\/span\u003e\u003c\/li\u003e \u003cli\u003e\u003cspan style=\"font-size:16px;\"\u003e\u003cstrong\u003eNew NGK spark plug\u003c\/strong\u003e to ensure proper ignition on startup\u003c\/span\u003e\u003c\/li\u003e \u003c\/ul\u003e \u003ch3 style=\"color:#c00;margin:20px 0 6px;text-align:center;\"\u003e⚙️ Fitment \u0026amp; Performance Compatibility\u003c\/h3\u003e \u003cp style=\"text-align:center;\"\u003e\u003cspan style=\"font-size:16px;\"\u003e Engineered as a direct-fit performance upgrade for Honda’s legendary air-cooled 400 platform. \u003c\/span\u003e\u003c\/p\u003e \u003cul\u003e \u003cli\u003e\u003cspan style=\"font-size:16px;\"\u003eHonda TRX400EX – All Years\u003c\/span\u003e\u003c\/li\u003e \u003cli\u003e\u003cspan style=\"font-size:16px;\"\u003eHonda TRX400X – All Years\u003c\/span\u003e\u003c\/li\u003e \u003cli\u003e\u003cspan style=\"font-size:16px;\"\u003eHonda XR400 – All Years\u003c\/span\u003e\u003c\/li\u003e \u003cli\u003e\u003cspan style=\"font-size:16px;\"\u003e397cc air-cooled Honda 400 engine platform\u003c\/span\u003e\u003c\/li\u003e \u003cli\u003e\u003cspan style=\"font-size:16px;\"\u003eClosed-course competition and racing applications\u003c\/span\u003e\u003c\/li\u003e \u003c\/ul\u003e \u003ch3 style=\"color:#c00;margin:20px 0 6px;text-align:center;\"\u003e❓ Frequently Asked Questions (FAQ)\u003c\/h3\u003e \u003cul\u003e \u003cli\u003e\n\u003cspan style=\"font-size:16px;\"\u003e\u003cstrong\u003eQ: Is this everything needed for a full top end rebuild?\u003c\/strong\u003e\u003c\/span\u003e \u003cp style=\"text-align:left;margin:0 0 10px 0;\"\u003e\u003cspan style=\"font-size:16px;\"\u003e\u003cstrong\u003eA:\u003c\/strong\u003e Yes. This kit includes the 89mm cylinder, forged piston kit, rings, wristpin, circlips, full Cometic gasket kit, MLS head gasket, Stage 3 camshaft, heavy-duty cam chain, SKF cam bearings, titanium head studs, and NGK spark plug.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e \u003cli\u003e\n\u003cspan style=\"font-size:16px;\"\u003e\u003cstrong\u003eQ: Which forged piston brand will I receive?\u003c\/strong\u003e\u003c\/span\u003e \u003cp style=\"text-align:left;margin:0 0 10px 0;\"\u003e\u003cspan style=\"font-size:16px;\"\u003e\u003cstrong\u003eA:\u003c\/strong\u003e Pistons are supplied from Wiseco, Wossner, JE, or CP depending on current inventory. You are welcome to contact us with a preference before ordering, but we cannot guarantee a specific brand — only what is currently in stock.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e \u003cli\u003e\n\u003cspan style=\"font-size:16px;\"\u003e\u003cstrong\u003eQ: Will this increase horsepower and torque?\u003c\/strong\u003e\u003c\/span\u003e \u003cp style=\"text-align:left;margin:0 0 10px 0;\"\u003e\u003cspan style=\"font-size:16px;\"\u003e\u003cstrong\u003eA:\u003c\/strong\u003e Absolutely. The 440cc big bore combined with the Stage 3 camshaft significantly increases bottom-end torque, midrange pull, and top-end horsepower.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e \u003cli\u003e\n\u003cspan style=\"font-size:16px;\"\u003e\u003cstrong\u003eQ: Is the cam chain upgraded from OEM?\u003c\/strong\u003e\u003c\/span\u003e \u003cp style=\"text-align:left;margin:0 0 10px 0;\"\u003e\u003cspan style=\"font-size:16px;\"\u003e\u003cstrong\u003eA:\u003c\/strong\u003e Yes. Our BPRATV Talon Heavy Duty cam chain is thicker and wider than OEM chains for added durability under high-performance loads.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e \u003c\/ul\u003e \u003ch3 style=\"color:#c00;margin:20px 0 6px;text-align:center;\"\u003e🌟 Why Buy from BPRATV? Trusted Honda Performance Experts 🌟\u003c\/h3\u003e \u003cp style=\"text-align:center;margin:0 20px;\"\u003e\u003cspan style=\"font-size:16px;\"\u003e At BPRATV, our promise is unwavering: \u003cstrong\u003eThe Best Parts. The Best Performance.\u003c\/strong\u003e We specialize in high-performance Honda ATV and dirt bike engine builds and ship premium 400EX rebuild kits fast — often by the next business day. No one sells more high-quality 400EX rebuild kits. Trust BPRATV to keep your Honda TRX400EX, TRX400X, or XR400 running at its best, every single time. \u003c\/span\u003e\u003c\/p\u003e \u003cp style=\"text-align:center;margin:0 20px;\"\u003e\u003cspan style=\"font-size:16px;\"\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/p\u003e \u003cp style=\"text-align:center;margin:0 20px;\"\u003e\u003cspan style=\"color:#38761d;font-size:16px;\"\u003e\u003cstrong\u003e\u003cem\u003eBuild it right. Build it once. Upgrade to 440cc power today!\u003c\/em\u003e\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e \u003cp style=\"text-align:center;margin:0 20px;\"\u003e\u003cspan style=\"font-size:16px;\"\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/p\u003e \u003cp style=\"text-align:center;margin:0 20px;\"\u003e\u003cspan style=\"color:#0000ff;font-size:16px;\"\u003e\u003cstrong\u003eBPRATV - The Best Parts. The Best Performance. The Best Price.\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e \u003cp style=\"text-align:center;margin:0 20px;\"\u003e\u003cspan style=\"color:#0000ff;font-size:16px;\"\u003e\u003cstrong\u003eBRAPPPPPPPPPP!\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e \u003cp style=\"text-align:center;font-size:10px;color:#555;margin:20px 0 0px;\"\u003e© BPRATV LLC 1-year limited warranty from the manufacturer for material or workmanship defects.*\u003cbr\u003e\u003cbr\u003e Due to the nature of high performance and racing applications, BPRATV LLC components are sold without express warranty or any implied warranty of merchantability or fitness for a specific purpose. BPRATV LLC shall not, under any circumstances, be liable for any specific, incidental or consequential damages, including, but not limited to, damage, or loss of property or equipment, loss of profits or revenue(s), cost of purchased or replacement goods, or claims of customers of the purpose, which may arise and\/or shall result from sale, installation or use of these parts. Installation of these parts may void vehicle manufacturers warranty coverage and\/or may cause the vehicle to be illegal in some locations. \u003cbr\u003e\u003cbr\u003e This product is exempt from the emission standards and related requirements of 40 C.F.R. § 1051 as provided by 40 C.F.R. § 1051.620, and California law [e.g., vehicle code§§ 27156 and 38391]. This product is sold only for use in connection with EPA-certified, purpose-built, nonroad vehicles used solely for closed course, nonroad competition\/racing and not used for any recreational purpose or on public highways or rights of way maintained by and open to the public. This product is sold only in connection with machines that do not fall under state and\/or federal noise or emission standards\/regulations. Purchasers who purchase this product represent and warrant that the product is purchased only in connection with EPA-certified, emission-regulations-exempt and noise-regulations-exempt competition\/racing vehicles as interpreted under applicable state and\/or federal law.\u003c\/p\u003e \u003c\/div\u003e \u003c!-- eBay Listing Titles (79-80 Characters Each): Honda TRX400EX 440 Big Bore Kit 89mm Stage 3 Cam Titanium Studs Rebuild TRX400EX 400X XR400 89mm 440 Big Bore Kit Stage 3 Hot Cam Complete Kit Honda 400EX 440cc Big Bore 89mm Cylinder Stage 3 Cam Top End Rebuild 400EX 440 Big Bore Kit Hot Cams Stage 3 Wiseco Cometic Titanium Studs Honda TRX400EX XR400 400X 440 Big Bore Complete Engine Rebuild Kit Recommended eBay Product Category: ATVs, Parts \u0026 Accessories \u003e ATV, Side-by-Side \u0026 UTV Parts \u003e Engines \u0026 Components Recommended Secondary Category: Motorcycle \u0026 Scooter Parts \u0026 Accessories \u003e Engines \u0026 Engine Parts \u003e Cylinders Broad Match Keywords: TRX400EX 440 big bore kit 400EX 89mm cylinder XR400 440 piston kit 400X top end rebuild Stage 3 cam 400EX Honda 400EX titanium head studs Cometic 400EX gasket kit Wiseco 400EX piston Hot Cams 400EX BPRATV 440 kit 400EX engine rebuild kit Honda 400EX performance kit Meta Title: Honda TRX400EX 440 Big Bore Kit 89mm Stage 3 Cam Rebuild honda-400ex-400x-xr400-440cc-big-bore-kit-89mm-hotcams-stage3 Meta Description: Complete Honda TRX400EX 440 big bore kit with 89mm cylinder, Stage 3 cam, forged piston, titanium head studs, Cometic gaskets and heavy-duty cam chain. --\u003e","brand":"BPRATV","offers":[{"title":"Default Title","offer_id":41856238911685,"sku":"284358613380\/4667M08900*\/C7826\/1051-3\/3P-440","price":760.74,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0593\/1083\/3861\/files\/284358613380-0.jpg?v=1771966128","url":"https:\/\/bpratv.com\/products\/honda-trx400ex-440cc-big-bore-kit-stage-3-hot-cam","provider":"BPRATV","version":"1.0","type":"link"}