Looking to enhance your Honda 400EX’s performance or keep it running smoothly? Our comprehensive shopping guide for 400EX parts is tailored for every rider—from casual enthusiasts to seasoned off-roaders. Discover trusted upgrades, maintenance essentials, and top tips for selecting the best components to match your needs and budget. Revitalize your ride and ensure every adventure is unforgettable with the right 400EX parts!
400EX Parts: Types, Variations, and Applications
Upgrading and maintaining your Honda TRX400EX ATV requires a solid understanding of the different aftermarket and OEM parts available. Each component—whether it’s for performance tuning, durability, or style—serves a unique function. Here’s a comparative table to give you a quick overview of widely sought-after 400EX parts, their main characteristics, and their most common applications:
| Part Category | Main Variations | Use/Application | Typical Materials | Key Brands |
|---|---|---|---|---|
| Engine Components | Pistons, Gasket Kits, Valve Kits, Camshafts | Power upgrades, engine rebuilds | Aluminum, Steel | CT Racing, Tusk |
| Air Intake/Filters | Foam Filters, K&N, Powerlids, Pre-filters | Improved airflow, engine longevity | Foam, Cotton, Plastic | K&N, Uni, Dura Blue |
| Exhaust Components | Full systems, Pipe kits, Spark Arrestors | Power & torque increase | Stainless steel, Aluminum | CT Racing |
| Drivetrain | Sprockets, Chains, Axles | Power transfer, gear ratio change | Steel, Alloy, Chromoly | JT, Sunstar, Lone Star |
| Suspension & Chassis | A-Arms, Swing Arms, Shocks, Steering Stems | Improved handling & stability | Chromoly, Aluminum | Lone Star Racing |
| Brakes | Pads, Rotors, Levers | Stopping power, reliability | Sintered metal, Steel | Tusk, EBC, Neutron |
| Electrical | Batteries, Cables, Plugs | Reliable starts, ignition | Lithium, Lead-acid | NGK, Tusk |
| Controls/Ergonomics | Handlebars, Levers, Guards | Rider comfort & control | Aluminum, Steel, Plastic | Renthal, Tusk |
How to Choose 400EX Parts: Quality, Customization, and Durability
1. Quality Indicators for 400EX Parts
When shopping for 400EX parts, quality should be your top priority. Look for:
- Material Grade: Parts made from 4130 chromoly steel, aerospace-grade aluminum, or premium alloys often outlast and outperform standard alternatives.
- Brand Reputation: Established brands like Lone Star Racing, CT Racing, K&N, and Tusk have proven track records. Check for customer reviews, warranty policies, and support services.
- Fitment Accuracy: OEM specification parts guarantee compatibility; reputable aftermarket brands also list precise fitment years and models.
- Certifications: Components that meet or exceed industry standards (such as ISO or factory-matched tolerances) ensure long-term reliability.
2. Customization Options for 400EX Parts
Customization allows you to tailor your ATV for your riding style, terrain, and needs:
- Performance Packages: Kits like 440cc big bore engines, ported heads, and custom carburation deliver noticeable gains in horsepower and torque.
- Adjustable Suspension: Wider or longer A-arm kits (+2” or +3”), along with aftermarket shocks, can be tuned for cross-country, dunes, or motocross setups.
- Ergonomics: Anti-vibe steering stems, premium grips, and leverage-adjustable levers reduce fatigue and improve comfort for longer rides.
- Appearance: Colored plastics, anodized hardware, and billet accessories help you stand out while also adding protection or function.
3. Durability: What to Look For
Durability translates to fewer breakdowns, longer maintenance intervals, and better overall value:
- Weld Quality: Clean, uniform welds—especially on structural parts like A-arms and swingarms—are essential for safety.
- Corrosion Protection: Powder-coating, anodizing, or stainless components withstand harsh weather and muddy conditions.
- Bolt-On Design: Select parts built for easy installation and removal; this facilitates maintenance and enables field repairs.
- Warranty Support: Long or lifetime warranties reflect a manufacturer’s confidence in their product’s lasting performance.
Practical Tips and Best Practices for 400EX Parts Selection and Use
Choosing, installing, and maintaining 400EX parts doesn’t have to be overwhelming. Use these expert tips:
- Confirm Fitment for Your Model Year: Some components vary between 1999–2004 and 2005–2014 400EX models (e.g., sprocket teeth count, wiring). Always double-check compatibility before ordering.
- Match Engine and Intake Upgrades: Installing a performance exhaust or big bore kit? Upgrade your air filter and re-jet your carburetor to balance air-fuel ratios and protect the new setup.
- Upgrade in Stages: Prioritize safety and reliability (brakes, suspension, controls) before adding performance parts.
- Keep Essential Spares: Carry extra levers, cables, spark plugs, and pre-filters for extended rides.
- Routine Inspection: Regularly check torque on fasteners, chain tension, and air filter cleanliness to prolong part life.
- Follow Proper Break-in Procedures: After major engine or suspension work, follow recommended break-in steps to ensure longevity and performance.
- Document Your Upgrades: Keep records of mods and maintenance. This helps troubleshooting and can increase resale value.
Comparing Key Technical Features of 400EX Parts
Here’s a comparison chart of the technical features and specs for some of the most popular 400EX aftermarket upgrades:
| Part / Feature | Example Models / Brands | Key Specs/Variations | Price Range | Key Benefits |
|---|---|---|---|---|
| Sprockets | JT, Sunstar | 13T, 14T, 15T Front (Year specific) | $11–$17 | Gear ratio tuning, durability |
| Air Filters | K&N, Dura Blue, Uni, Twin Air | Foam or cotton, stock or Powerlid type | $17–$70 | More airflow, better engine protection |
| Big Bore Engine Kits | CT Racing | Up to 440cc, hi-comp piston, cam | $1,335–$2,999 | 30%+ more horsepower |
| Exhaust Systems | CT Sonic | Stainless header, 12-disc muffler | $569+ | Increased HP, deep sound |
| A-Arm Kits (Suspension) | Lone Star Racing | +2”, +3”, chromoly, camber-adjustable | $845–$1,155 | Improved cornering, stability |
| Axles | Lone Star Axcalibar Pro | Race-ready, chromoly construction | $645+ | Strength, width adjustability |
| Clutch Kits | Tusk, OEM | With heavy-duty springs, stock replacement | $52–$55 | Enhanced power transfer, longevity |
| Brake Pads | Tusk, EBC, Neutron | Sintered or organic compound | $14–$35 | Strong braking, fade resistance |
| Batteries | Tusk, OEM | Lithium ($110+) or lead-acid ($43+) | $43–$110 | Weight savings, cranking power |
| Handlebar Controls | Renthal, Tusk | 7/8″ (stock), anti-vibe options, colors | $16–$23 | Comfort, reduced vibrations |
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Conclusion
Selecting the right 400EX parts empowers you to get more from your Honda TRX400EX—whether you’re after more power, better handling, or improved reliability. Focus on quality, compatible customization, and proven durability to ensure every upgrade pays off both on the trail and in the garage. Carefully chosen aftermarket and OEM parts not only boost performance and appearance but also add years of dependable fun to your ATV.
FAQ
-
What are the must-have upgrades for a stock 400EX?
Start with high-quality air and oil filters, durable chain and sprocket sets for reliability, and sintered brake pads for safe stopping. Suspension A-arms and upgraded shocks enhance handling, while a slip-on exhaust and air filter deliver a modest power bump. -
How do I know if a part fits my year of 400EX?
Always check the part manufacturer’s fitment guide. Some parts differ between early (1999–2004) and late (2005–2014) models, especially in sprockets, electricals, and carburation. -
What’s the benefit of a big bore kit or engine upgrade?
A big bore kit (like the 440cc packages) significantly increases power and torque, ideal for racers or dune riders. These kits often include forged pistons, revised cams, and ported heads for all-around performance improvement. -
Are aftermarket air filters worth it?
Yes, quality aftermarket filters (K&N, Uni, Dura Blue) expand airflow and filter efficiency, protect your engine, and are often washable and reusable—saving money over time. -
How do I choose the right sprocket size?
Lower tooth counts on the front sprocket (like 13T) provide quicker acceleration but reduce top speed. Higher counts (like 15T) boost top speed but mellow out low-end thrust. Always choose based on your terrain and riding style. -
What’s the difference between OEM and aftermarket parts?
OEM (Original Equipment Manufacturer) parts match factory specs precisely for fit and reliability. Aftermarket parts can offer upgraded materials, performance, and styling—often at a lower cost or with added features. -
How can I improve my 400EX’s handling for racing?
Install wider A-arm kits (+2” or +3”), upgrade to longer or better shocks, fit a reinforced rear axle, and consider anti-vibe steering stems for more precise, fatigue-free control. -
How often should I replace my 400EX’s wear parts?
Replace filters, chains, sprockets, and brake pads as needed—usually every 2,000–3,000 miles or sooner in harsh conditions. Always inspect after muddy rides or races. -
Are there plug-and-play electrical upgrades?
Yes, lithium batteries, upgraded spark plugs, and heavy-duty wiring kits are designed for easy installation. Check compatibility for your model year and follow all safety precautions. -
Can I install most upgrades myself?
Many bolt-on parts like levers, sprockets, filters, and slip-on exhausts are DIY-friendly. Engine internals, suspension swaps, and carb tuning often require intermediate to advanced mechanical skills or professional installation for best results.