2005 Honda 400EX Sportrax Specs, Price & Review 2024
The Honda 400EX Sportrax is one of the most popular mid-sized 4×4 ATVs ever made. Introduced in 1999, this venerable quad offered the perfect blend of power, handling and reliability for recreational trail and sport riding.
In this in-depth review, we’ll take a close look at the 2005 Honda 400EX model. What engine does the 400EX have? How fast does it go? What are the key specs and features? How much does a used 400EX cost? Let’s find out!
Table of Contents
Overview Of The 2005 Honda 400EX Sport ATV
The Honda 400EX began life in 1999 as the successor to the popular 300EX. This new sport-utility quad featured a larger 397cc air-cooled four-stroke single-cylinder engine, giving it a nice boost in power over the 300EX.
The 400EX was built on a steel frame with dual A-arm front suspension and a single shock swingarm rear end. It had hydraulic disc brakes front and rear for strong stopping power. The 400EX utilized a 5-speed manual transmission with a manual clutch and reverse gear.
This combination of engine performance, sporty handling and rider-friendly ergonomics made the 400EX a hit for recreational riders. It was great for trail riding and racing, yet docile enough for new riders. Experienced riders could push the 400EX to its limits and still have a grin on their face.
The 2005 Honda 400EX saw no major changes from the previous model years. It retained the same 397cc air-cooled powerplant, 5-speed transmission, push button electric start and manual clutch.
Competition-wise, the 400EX went up against other popular 400cc class sport quads like the Suzuki LT-Z400 and Kawasaki KFX400. Let’s take a closer look at the engine and transmission in the 2005 400EX.
2005 Honda 400EX Engine And Transmission
At the heart of the 2005 400EX is the proven 397cc air-cooled SOHC single-cylinder four-stroke engine. This provides a good balance of easy-riding power with Honda’s legendary reliability. Here are some key engine specs:
- Displacement: 397cc
- Bore and stroke: 85mm x 70mm
- Compression ratio: 9.1:1
- Carburetion: Keihin 36mm flat slide carb
- Ignition: CD with electronic advance
- Starting: Electric start
This single-cylinder motor churns out around 28 horsepower, allowing the 400EX to reach a top speed around 65–72 mph depending on conditions and mods. Low-end and mid-range power is excellent, providing strong acceleration whether riding trails or pulling wheelies.
The 400EX has a 5-speed manual transmission with a manual clutch and reverse gear. The clutch offers good feel and smooth engagement. Shifting is effortless through the gearbox even under aggressive riding.
The transmission ratios are well spaced, providing snappy acceleration in lower gears while maintaining comfortable highway cruising. The electric start button allows easy starting with the simple press of a button.
2005 Honda 400EX Sportrax Key Features And Specs
In addition to the engine and transmission, the 2005 400EX boasts some impressive specs and features:
| Spec | Measurement |
|---|---|
| Engine | 397cc air-cooled SOHC single-cylinder |
| Transmission | 5-speed manual w/ reverse |
| Horsepower | 28 hp |
| Starting | Electric start |
| Dry Weight | 388 lbs |
| Seat Height | 31.9 inches |
| Ground Clearance | 9.1 inches |
| Fuel Capacity | 2.7 gallons |
| Front Suspension | Independent double wishbone, 5.3 inches travel |
| Rear Suspension | Swingarm, 5.0 inches travel |
| Front Brakes | Dual hydraulic disc |
| Rear Brakes | Single hydraulic disc |
| Front Tires | 22 x 7R-10 |
| Rear Tires | 22 x 10R-9 |
Key Features
With nearly 10 inches of ground clearance and long suspension travel, the 400EX can attack rough trails with ease. The double A-arm front and single swingarm rear end soak up bumps extremely well.
Stopping comes courtesy of hydraulic disc brakes on both ends with strong, consistent power. The front utilizes a twin-piston caliper while the rear has a single-piston caliper.
The 400EX rolls on 22-inch Maxxis tires front and rear. The front tires measure 22 x 7R-10 while the rears are 22 x 10R-9. This provides a balanced footprint for responsive steering and ample traction.
Some other great features include a high-mount exhaust, removable skid plates for trail protection, comfortable seat, and an easy-to-read digital meter. There is also a retractable passenger seat peg for taking a friend along for the ride.
2005 Honda 400EX Top Speed, Pricing And MPG
With its 397cc powerplant, the 2005 Honda 400EX can reach a top speed around 65–72 mph depending on conditions, mods and rider weight. It has sufficient power for highway riding although the suspension is better tuned for trails and lower speed riding.
Used pricing for a 2005 Honda 400EX can vary quite a bit depending on the miles, condition, and any mods or accessories added. In general, expect to pay:
- Excellent condition with low miles: $3,000 – $3,500
- Good condition with average miles: $2,500 – $3,000
- Higher miles or rough condition: $1,800 – $2,500
These prices will fluctuate based on location and local market demand. Be sure to inspect any used 400EX thoroughly before purchasing.
As for gas mileage, the 400EX will achieve around 30 mpg combined depending on how it is ridden. Aggressive use will drop mileage into the high 20s, while more conservative riding can see 32+ mpg. The relatively small 2.7 gallon tank means frequent fill ups will be necessary if spending a full day on the trails.
Performance And Handling
The foundation of the 400EX’s excellent performance is the responsive 397cc engine. It produces usable grunt right off idle, pulling strongly through the rev range. The powerband is very broad, allowing the rider to keep momentum in any gear without constant shifting.
Throttle response is crisp without any hiccups or flat spots in the power delivery. Dialing on the throttle will loft the front end easily if desired. Experienced riders may want to add an exhaust and rejet the carb for even more top end.
Matching the willing engine is the sport-tuned long travel suspension. It offers 9.1 inches of ground clearance to traverse rocky obstacles with ease. The double A-arm front end and single rear swingarm provide a plush ride that soaks up harsh impacts extremely well.
On the trail, the 400EX handles impressively, able to carve up singletrack and technical sections at speed. The chassis feels stable and precise, backed up by quality braking power. The quad is very flickable side-to-side.
High speed handling is also quite good for a pure sport quad. The front end will push a bit in the whoops but the 400EX tracks straight and remains composed. All said, it’s one of the best handling mid-sized sport quads thanks to the dialed-in suspension quality.
Safety Features
The 400EX offers a good array of safety features as expected from Honda. First up is the excellent braking system using hydraulic discs on both ends. The twin-piston front caliper and 240mm disc provide strong, consistent stopping power with good feel.
ABS was not offered in 2005 but the brakes have plenty of power for the street-legal 400EX. The Maxxis Weeline tires also feature a stiff sidewall for stability during hard braking.
Chassis and suspension safety comes from the rugged steel frame paired with long travel suspension. This allows the rider to avoid obstacles or land big jumps thanks to over 9 inches of ground clearance. The dual A-arms up front provide precise steering.
Finally, Honda equipped the 400EX with durable plastic guards to protect the rider in the event of a tip over. It has front and rear fender guards, plus a skid plate guarding the engine cases. Hand guards add protection during falls.
Pros And Cons Of The 2005 Honda 400EX
Pros
- Powerful 397cc engine with excellent power delivery
- Smooth and durable 5-speed transmission
- Strong brakes with hydraulic discs front and rear
- Excellent suspension soaks up bumps and provides great handling
- Reliable electric start with backup kick starter
- Quality Maxxis tires for traction and durability
- Proven Honda reliability and build quality
- Good ergonomics for tall or short riders
Cons
- Heavy at 388 pounds dry weight
- No fuel injection means tuning the carburetor
- Small 2.7 gallon fuel tank limits range
- No advanced features like GPS or EFI
- Discontinued in 2007 so fewer OEM parts available
- Not as powerful as a 450cc sport quad
Top Speed, Pricing By Year And MPG
Let’s take a closer look at how the 400EX’s top speed, pricing and gas mileage compare across different model years:
Top Speed
The 400EX’s top speed remained consistent from 1999-2007 around 65–72 mph in stock form depending on conditions. Horsepower and engine performance essentially stayed the same throughout the production run.
Pricing by Year
| Year | Original MSRP | Used Price Range |
|---|---|---|
| 1999 | $5,799 | $1,500 – $2,800 |
| 2000 | $5,999 | $1,600 – $3,000 |
| 2001 | $6,199 | $1,800 – $3,200 |
| 2002 | $6,399 | $2,000 – $3,500 |
| 2003 | $6,499 | $2,200 – $3,800 |
| 2004 | $6,599 | $2,500 – $4,000 |
| 2005 | $6,799 | $2,800 – $4,200 |
| 2006 | $6,999 | $3,000 – $4,500 |
| 2007 | $7,199 | $3,200 – $4,800 |
Prices rise steadily for both new and used quad. As you would expect, the older and higher mileage 400EX models command less money on the used market compared to later years. Overall condition has a big impact on resale value.
Gas Mileage
The 400EX averaged around 30 mpg combined across all years. Riding style impacts mpg greatly – expect 23-27 mpg with very aggressive use, and 32+ mpg with milder trail riding. The 2.7 gallon tank allows about an 80 mile range under normal conditions.
Performance Upgrades
One great benefit of the Honda 400EX platform is the huge range of performance parts available. Here are some of the most common upgrades owners add:
- Exhaust – Aftermarket slip-ons and full systems enhance power while reducing weight. Popular brands include Yoshimura, ProCircuit and Two Brothers.
- Air filter – An aftermarket air filter like a K&N will allow more airflow and add a couple extra ponies.
- Jet kit – Rejetting the carburetor optimizes fueling to match intake and exhaust mods.
- Programmer – An ignition programmer provides more precise fuel/spark mapping for the mods. Dynojet Power Commander is popular.
- Suspension – Stiffer springs, better shocks and lowered ride height improve handling for aggressive riders. Elka, Fox and Works Performance upgrade suspension.
- Tires – More aggressive aftermarket tires like Maxxis Razr MX or ITP Holeshot offer increased traction and durability for motocross riding.
- Clutch kit – A Rekluse clutch kit offers improved modulation and grip for hard launches and slippage control.
- Bumper – Adding a bumper or rear grab bar improves protection during falls and tip overs. Popular brands are Maier, Pro Armor and Rough Country.
With the right combination of performance upgrades, the 400EX can gain 5-8 horsepower at the wheels. This transforms the mild-mannered quad into a burly hill climber and trail blaster without reliability sacrifices.
Common Issues and Solutions
The Honda 400EX enjoys a reputation for rock-solid reliability when properly maintained. However, they are not flawless. Here are a few common issues to look out for:
Leaking Front Differential
This manifests as a wet area around the front diff case. Resealing the diff assembly with fresh seals and fluid will repair the leak. Use only Honda recommended fluid.
Burning Oil
Excessive smoke from the exhaust, especially under acceleration, can indicate worn piston rings or valve guide seals. A top end rebuild may be necessary in severe cases of oil burning.
Hard Starting
Difficulty getting the engine to fire can be caused by a few issues: weak battery, dirty carburetor, bad fuel pump or plugged exhaust. Try starting fluid to narrow down the cause.
Sticking Throttle
Dirt and corrosion in the throttle cable/housing can cause a sticky throttle that is slow to return. Disconnect and lubricate the cable. Replace if binding persists.
Overheating
400EX models operated in deep mud or heavy sand can overheat the engine. Improving airflow by unclogging blocked radiator fins can help. Adding an auxiliary radiator provides extra cooling capacity.
Shifting Problems
Labored shifting, jumping out of gear or grinding can be due to low transmission fluid, worn shift forks or damaged gears. Inspect fluid level first before tearing into the transmission.
Rear Axle Wear
Excessive vibration or clacking noises from the rear end points to worn bearings or other internal damage. A rear axle/swingarm rebuild or replacement will be needed in severe cases.
Thankfully, dedicated owners have kept the 400EX community thriving since production stopped in 2007. Plenty of used OEM and aftermarket parts are still available. Basic maintenance and prompt repair of issues will keep a 400EX running strong for years.
What Owners Are Saying?
With its great balance of user-friendly power, nimble handling and Honda reliability, it’s easy to see why owners praise the 400EX quad. Here are some comments directly from owners:
“The best all-around midsize sport quad I’ve owned. Tons of power for trails or track. Easy to ride fast and very dependable.”
“Awesome machine! Starts easy cold or hot, runs super strong and handles like a dream. Just change the oil and adjust the valves.”
“My son learned to ride on a 400EX and loves it. He can keep up with me on the trails and it always gets him home safe.”
“She’s 18 years old and still running strong! Starts first kick thanks to diligent maintenance. These things last forever.”
“Perfect size for trail riding. The 397cc engine has plenty of torque without being intimidating. Still quick enough to have fun.”
Of course, not every owner has had a flawless experience. Here are some critical owner comments:
“The stock carb is terrible. Nearly impossible to jet properly. Finally swapped on a Mikuni and it runs like a champ now.”
“Kept blowing out rear brakes in muddy and wet conditions. Had to upgrade to aftermarket pads and rotors.”
“It throws the chain occasionally if you ride hard in sand or deep ruts. Frustrating issue that I never fully solved.”
“The 2.7 gallon tank seems small – you’re constantly looking for gas. I installed a larger IMS tank for more range.”
“Not the best quad for tall or bigger riders. I’m 6’2″ and felt cramped. Lack of adjustments made it uncomfortable.”
Overall though, owners agree that a well-maintained 400EX is an incredibly fun and capable quad. Its reliability and performance make it a top choice for recreational trail and sport riding.
Top 10 Alternative ATVs
The 400EX carved out its own niche that has been tough to replicate since going out of production. However, here are 10 popular alternatives that can match its capabilities:
- Suzuki LT-Z400 – Closest 400EX competitor has similar 399cc engine and performance.
- Yamaha Raptor 350 – Proven 348cc sport quad great for new riders.
- Kawasaki KFX450R – More powerful 449cc engine pushes 50+ hp.
- Arctic Cat DVX400 – 400cc Suzuki-built engine, 2WD/4WD models available.
- Polaris Outlaw 525 IRS – 525cc V-twin IRS sport quad. Larger but very capable.
- Honda TRX450R – Race-inspired 450cc sport ATV offers lighter weight.
- Can-Am DS450 – Rotax 449cc V-twin pumps out 40+ hp for dune riding.
- Yamaha Banshee 350 – Legendary 350cc twin is a beast but two-stroke only.
- Kawasaki KFX450 – 4-stroke 450cc option great for motocross tracks.
- Yamaha Blaster 200 – Two-stroke 200cc engine in a smaller sporty package.
While the above quads can match the 400EX in performance, finding one with the same longevity and reliability is difficult. The Honda stands in a class of its own thanks to its engineering and durability.
Verdict – Is The 2005 400EX A Good Buy?
The 2005 Honda 400EX remains an excellent mid-sized sport quad choice over 15 years after its release. It strikes a fantastic balance between user-friendly power, nimble handling, reliability and value. Simply put, it’s one of the best all-around sport ATVs ever made.
While the performance won’t match the latest 450cc motocross models, the 397cc engine offers ample grunt for recreation. Mild mods can coax out even more power. The 5-speed transmission is buttery smooth and tough as nails.
The real standouts are the supple suspension and excellent chassis dynamics. The long travel double A-arm front end and rear swingarm provide a plush ride that translates to superb handling. This Honda loves carving up trails and cornering hard.
Durability is yet another strong point for the 400EX. The proven 397cc engine will run for thousands of miles if maintained. The transmission, cooling system and other components are built to last in the face of hardcore abuse.
Compared to modern fuel injected models, the 400EX may feel a bit dated. But it starts reliably with the push of a button and runs consistently despite the old-school carburetor. Owners that stay on top of maintenance are rewarded with years of faithful service.
For recreational riders that want a nimble sport quad with easy-riding power, terrific handling and ironclad durability, the 2005 Honda 400EX delivers in spades. It provides big fun in a mid-sized package without intimidating new riders.
In the used market, the 400EX is also an incredible value starting around just $2,000. The abundant aftermarket parts keep repair costs low long after Honda stopped making them. There’s simply no better choice for an affordable, do-it-all sport quad.
While the glory days of the 400EX have passed, its potent blend of versatility, user-friendly power and rock-solid reliability cement its status as a legend. For riders that appreciate durability as much as performance, the trusty 2005 Honda 400EX remains a top option when shopping for a used sport ATV.
Conclusion
The 2005 Honda 400EX demonstrates why this sport quad achieved such widespread popularity. Its 397cc air-cooled engine provides a healthy dose of power while maintaining Honda’s famed reliability.
Matched to the responsive engine is a dialed-in chassis and long travel suspension that soak up trails while providing sharp handling. Stopping power is excellent thanks to hydraulic discs at both ends.
While the 2.7 gallon tank limits range, the 400EX makes up for it with nimble handling and ample performance for recreational trail and track use. Its easy-going disposition also makes it a great learner quad.
In total, the 2005 400EX delivers fantastic performance, plush suspension, proven reliability and tremendous value in the used market. It’s easy to see why many owners consider it one of the best all-around sport quads ever produced.
