GOOFIT
85mm 397cc Big Bore Cylinder Rebuild Kit with Piston & Gaskets for Honda TRX400EX TRX400X XR400R (1996-2014)
85mm 397cc Big Bore Cylinder Rebuild Kit with Piston & Gaskets for Honda TRX400EX TRX400X XR400R (1996-2014)
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Product Overview
Restore the high-torque performance of your Honda ATV or Dirt Bike with the GOOFIT 85mm Cylinder Rebuild Kit. Engineered as a direct OEM replacement for the 397cc (400cc class) engine, this kit is compatible with the legendary XR400R and TRX400EX/X series. Crafted for precision and durability, it includes everything from the cylinder block to a premium spark plug and an exclusive GOOFIT keychain, ensuring your Quad or Pit Bike is ready for the toughest trails.
Product Compatibility
This kit is a precision-engineered replacement for the following Honda 4-stroke models:
| Model | Year Range | Vehicle Type |
| Honda XR400R | 1996–2004 | Dirt Bike / Enduro |
| Honda Sportrax TRX400EX | 1999–2008 | Sport ATV / Quad |
| Honda TRX400X | 2009, 2012–2014 | Sport ATV / Quad |
Specifications
| Attribute | Technical Details & Measurements |
| Cylinder Bore Size | 85.00mm (Standard 400cc Bore) |
| Displacement | 397cc |
| Mounting Nut Distance | 87mm x 80mm x 90mm x 80mm |
| OEM Reference Nos. | 12100-HN1-A70, 13101-KCY-670, 12251-HN1-003 |
| Material | High-Grade Aluminum Alloy with Steel Liner |
| Package Includes | Cylinder, Piston, Rings, Pin, Clips, Gaskets, Spark Plug, Keychain |
Key Features
- Perfect OEM Interchange: Designed to meet or exceed original factory specifications, ensuring a seamless fit with your Honda crankcase and head.
- Heavy-Duty Construction: Features a robust cylinder sleeve that provides excellent wear resistance and thermal stability, ideal for long-distance trail riding or racing.
- Enhanced Sealing System: Includes premium multi-layer gaskets and precision-machined piston rings to prevent compression loss and eliminate oil leaks.
- All-In-One Rebuild Package: Comprehensive kit including a performance spark plug and all necessary top-end hardware, saving you time and ensuring component compatibility.
- GOOFIT Quality Assurance: Every kit undergoes rigorous quality control to ensure "out-of-the-box" reliability for professional mechanics and DIY enthusiasts alike.
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Fitment FAQ
Will this part fit my specific model and year?
This cylinder piston kit is intended for Vehicle Type; Honda XR400R; 1996–2004; Dirt Bike / Enduro; Honda Sportrax TRX400EX; 1999–2008; Sport ATV / Quad. It is best matched to original part number(s) 1996-2014, 12100-HN1-A70, 13101-KCY-670, 12251-HN1-003. Key physical/spec details from the product data include Cylinder Bore Size: 85.00mm (Standard 400cc Bore), 85.00mm (Standard 400cc Bore), 85mm. Use the compatibility table and product photos together before ordering.
Do I need to match the OEM part number?
Yes. Match your original part number to 1996-2014, 12100-HN1-A70, 13101-KCY-670, 12251-HN1-003 before purchase. For this cylinder piston kit, also compare the bore diameter, piston-pin size, gasket pattern, stud spacing, engine code, stroke type, and cylinder height. This is especially important for Honda TRX400X/XR400R models because similar model names can use different parts by year or trim.
What models or situations does this part not fit?
Do not order this cylinder piston kit for machines outside the listed compatibility, or for units with different bore sizes, piston-pin diameters, stroke lengths, stud spacing, or gasket patterns. If your original part number does not cross-reference with 1996-2014, 12100-HN1-A70, 13101-KCY-670, 12251-HN1-003, treat the fitment as unconfirmed. Model years outside 1996–2014, 1996–2004, 1999–2008, 2012–2014, 1996 should be verified separately. Do not rely only on the model name or engine size.
What should I check before ordering?
Before ordering, compare your original part with the photos and check the bore diameter, piston-pin size, gasket pattern, stud spacing, engine code, stroke type, and cylinder height. Confirm OEM/cross-reference number(s): 1996-2014, 12100-HN1-A70, 13101-KCY-670, 12251-HN1-003. Recheck listed specs such as Cylinder Bore Size: 85.00mm (Standard 400cc Bore), 85.00mm (Standard 400cc Bore), 85mm. If any connector, mounting point, size, or year detail is different, confirm fitment before installation.