Another entry-level quad hailing from the prestigious Sportrax lineup, the 2007 Honda 400EX is many a rider’s go-to all-terrain vehicle. As a hybrid, it stands out from the competition.
Because of its well-balanced competencies as a woods and sport-oriented four-wheeler, people gravitate toward the iconic 400-class quad. And after knowing more about the 400EX from this guide, I am sure you will be too.
The 2007 Honda 400EX (a.k.a. Sportrax TRX400EX) is the 9th installment of the sport-utility series that rallied sport-quad racing. Boasting a Pro-Link rear linkage, 28-hp power output, aggressive styling, and an air-cooled 397-cc engine, the quad continues to captivate casual riders and enthusiasts.
Consumers had high expectations for the Honda 400EX when its incarnation came out in 2007. Many riders have long expected the wheeler to sport a belt drive, enhanced gearing, and better acceleration and power.
Whether or not the ATV was able to fulfill these presumptions is left for you to discover in this article.
2007 Honda 400EX: The Chevy S-10 of Quads
The 2007 Honda 400EX is a versatile, reliable, and well-loved sport-utility ATV and the 9th installment of the 400-cc Sportrax lineup first introduced in 1999. It is among the many forerunners to speed-hungry 450-class quads and is credited with the resurgence of sport-riding during the mid-2000s.
Like the classic Chevrolet S-10, the 2007 Honda Sportrax is a great all-rounder, adored for its familiar Red color and multifaceted handling mannerisms. Its discontinuation in 2009 is also one of the riding community’s greatest regrets.
2007 Honda 400EX Specs & Features (TRX400EX Sportrax®)
Engine
The 2007 Honda TRX 400EX comes to life via an electric starting system and an air-cooled, single-cylinder 4-stroke RFVC (Radial Four-Valve Combustion Chamber) power mill.
It has a bore-stroke ratio of 85 × 70 mm (3.35 × 2.76 inches), a 9.1:1 compression ratio, and a displacement of 397-cm3 (24.23 in3).
A 38-mm Keihin carburetor supplements pistons with an accelerator pump mated to an oiled urethane foam air filtration.
The above engine configuration translates to the following performance figures:
| Description | Performance Figure |
|---|---|
| Top Speed | 65–72 mph (105–116 km/h) |
| Horsepower | 28 RWHP (20.59 kW) @ RPM |
Fuel & Lubrication
Tank capacity remains unchanged at 10 L/2.64 USgal (including 1.6-L/0.42-USgal of reserve) of unleaded gasoline with a minimum octane rating of PON 87/RON 91. This capacity yields an average combined gas mileage of at least 35.3 mpg (6.7 L/100 km) per forums – which is why Sportrax users advise getting a 5.5 L Clarke tank or something similar, such as this large fuel tank (view on Amazon) to improve the quad’s fuel economy.
Permissible fuel variants should be unleaded gasoline containing no more than 5% MTBE (Methyl Tertiary Butyl Ether), 16.7% TAME (Tert–Amyl Methyl Ether), or 17.2% ETBE (Ethyl Tertiary Butyl Ether).
Oxygenates/gasohol blends with less than 10% ethanol or 5% methanol are also allowed. Note that using fuel variants with a lower octane rating is ill-advised, as doing so can cause persistent engine pinging or spark knock.
Lube-wise, the ’07 Honda Sportrax requires SAE 10W-40 Pro Honda GN4 or HP4 4-stroke motor oil with a minimum API grade of SJ, without “Energy Conserving” labels and graphite or molybdenum additives and meeting JASO T903 MA standards.
Other viscosity grades from the manual are permitted for use following changes in ambient temperature and riding conditions. Below are the four-wheeler’s engine oil requirements for your reference:
| Description | Quantity |
|---|---|
| After draining | 1.7 L (1.8 US qt) |
| At disassembly | 2.2 L (2.3 US qt) |
Drivetrain
A 5-speed constant-mesh (wide-ratio) transmission and a cable-operated wet, multi-plate clutch assembly deliver power to the ground. The clutch has a 1-N-2-3-4-5 shift sequence mated to an RK520SMOZ10S or DID520V6 O-ring sealed chain (94/120 links + joint) that handles wheelspin.
The 2007 TRX400EX also retains the reverse gear, which can activate via six easy steps detailed in a previous article on the 2005 Honda 400EX. The same goes for stock sprocket-gear ratios altered in 2005:
| Description | Ratio |
|---|---|
| Primary Reduction Ratio | 2.826 (23/65) |
| Final Reduction Ratio | 2.786 (14/39) |
| Transmission Gear Ratio – I | 2.727 |
| Transmission Gear Ratio – II | 1.789 |
| Transmission Gear Ratio – III | 1.363 |
| Transmission Gear Ratio – IV | 1.080 |
| Transmission Gear Ratio – V | 0.925 |
| Reverse Gear Ratio | 2.428 |
Ignition & Lighting
An electric starter, CDI with electronic advance, and ICM (or Ignition Control Module) with a neutral idle speed of 1,400 ± 100 RPM breathe life into the 2007 incarnation. Additionally, it requires an NGK DPR8Z or Nippon Denso X24GPR-U spark plug with a 0.6–0.7 mm (0.024–0.028 inch) gap for spark ignition.
A single-phase output alternator with a rated output of 0.147 kW @ 5,000 RPM serves as its charging system, while a YTX9-BS battery (view on Amazon) powers electronic accessories and lighting (itemized below):
| Description | Wattage |
|---|---|
| Headlight (Low/High) | 12V 30/30W x 2 |
| Brake/Taillight | LED |
| Neutral, Reverse Indicators | 12V 3.4W |
Tires & Brakes
Stock rubber consists of 22 x 7-10 (view on Amazon) M/R 101 front and 20 x 10-9 M/R 501 rear radials with a 4/110 or 4/144 bolt pattern. Front tires mount on 10×5.5 AT mags, while rear ones go on 9×8.0 AT rims.
These wheels mate to dual 174-mm hydraulic discs at the front and a single 220-mm hydraulic disc at the rear. For its braking system, the quad sports brake calipers on all fours.
Recommended cold-tire pressure for front and rear tires is 27 kPa (0.275 kgf/cm2, 4.0 psi) ± 15%. Depending on riding conditions, you may air down or inflate your tires, provided you do not go beyond 23 kPa to 31 kPa. The tread wear limit for factory tires is at least 3/16″ (4 mm).
Suspension
An independent, front double-wishbone with 5-way preload-adjustable Showa shocks and a Pro-Link rear swingarm with a fully adjustable Showa mono-shock is enclosed in a tubular steel frame (7° caster angle; 32-mm/1.3-inch trail) with a removable subframe.
Each suspension unit provides a respective wheel travel of 209 mm (8.2 inches) and 230 mm (9.1 inches).
The wheelbase is improved from 47.9 inches (1,217 mm) to 48.4 inches (1,229.4 mm), while minimum ground clearance saw a 4.9% increase from the previous year at 4.3 inches (109.2 mm).
The turning radius remains unchanged at 3.2 meters (10.5 feet). Thanks to upgrades received since 2005, the 2007 Honda 400EX can retain its superb ride quality and reduced unsprung weight.
Dimensions & Capacities
Slight adjustments were made to the four-wheeler’s overall dimensions, resulting in the following measurements: 72.2 x 45.3 x 43.7 inches (1,833 x 1,150.6 x 1,111 mm – L x W x H).
Saddle height still sits at 810 mm (31.9 inches) – same for the 353-mm/13.9-inch footpeg.
Dry weight is 175 Kg (386 lbs.). The GVWR is estimated at 292 Kg (643.75 lbs.), including a full tank, fluids, and the quad’s maximum load limit of 110 Kg (243 lbs.).
Controls & Exterior
The fuel valve, choke lever, and gear pedal is located on the left side of the engine, while the headlight/dimmer switches, parking brake levers, clutch levers, engine stop switch, and start button are near the left handgrip.
Conversely, the front brake fluid reservoir, reverse assist lever, front brake, and throttle levers are situated opposite the handgrips. Above the fuel tank are the neutral indicator lamp and ignition switch.
The standout difference between the ’05 and ’07 Sportrax models is their body panels. 2007 Honda 400EX plastics were available in several colors, not just Black and Red. But color schemes aside, one can barely tell the two incarnations apart.
Both have the label’s trademark narrow seat and impressive riding ergonomics, with their high-raise fenders (view on Amazon), urethane skid plates, and overall sport-oriented styling.
Cost of a 2007 Honda TRX 400EX
The list price of the Sportrax TRX400EX is $5,999, increasing by only $200 since receiving a slew of upgrades in 2005. Retail pricing averages $2,825, considered a competitive value when put against 400-class counterparts.
Kelley Blue Book data reveal resale values between $2,175 and $3,205 for secondhand units in good condition and with typical mileage. (Note that these figures are for base models only and exclude any performance add-ons.)
As for auction listings, values fall between $1,750 and $3,520. This price range is a bit higher compared to Nada Guides data. Units that fall on lower limits of the quad’s resale value spectrum are expected to have some part deformities or cosmetic damage like bent handlebars and front tie rods.
They are also rarely titled. On the bright side, these pre-loved wheelers are reportedly always in good running condition.
Highlights and Lowlights
Pros
- It has a nice suspension and an overall good all-rounder.
- Avid followers love that the 2007 Honda 400EX makes an awesome thumper sound.
- The addition of a reverse gear makes it a more economical choice than the KFX 400 or Z400.
- Riders don’t need to worry about their quad’s frame breaking or having to do tedious maintenance.
- Compared to same-class ATVs, the 2007 Honda 400EX has bigger aftermarket support.
- The 2007 Sportrax performs much faster in whoops, thanks to the improved suspension geometry and a more rigid swingarm.
- Come time for mods and upgrades, the TRX 400EX turns out more affordable than the KFX 400 or Z400.
- Adding Elka shocks and a GT Thunder rear link makes the 400EX feel like a 250R.
Cons
- One of the more apparent drawbacks of the TRX 400EX versus its competition is the absence of liquid cooling.
- The ’07 Sportrax does not have the best acceleration and top speed rating in its category.
- Wheelies are a tad too easy on the 400EX.
- Despite its tight rear suspension setup, it does not absorb bumps as effectively if you land tires first and at too much of an angle.
- The stock gearbox and clutch become weak points when the Honda 400EX gets beefed up.
- Cylinder heads are about the most expensive part to replace in a Sportrax and can cost as much as $600.
Since these lowdowns are based on secondhand Sportrax units, make sure to go over everything when purchasing one. The state of the quad is always largely dependent on how it was cared for by its previous owner.
That said, exercise due diligence in asking about any repair history and severity of usage. Never buy without test driving and checking the integrity of the start button, spark plug, and clutch. Inspect for wear on sprockets, and keep an ear out for unusual engine sounds. Lastly, verify that the axle and A-arms are not bent.
About Honda
Honda Motor Company Ltd. is a world-renowned forerunner of ATV and motorcycle industries and part of the Japanese “Big 4.” The Japanese firm is also the brains behind the highly lauded and successful Sportrax series, including the 2007 Honda 400EX.
Conceptualized in the Art Shokai garage in Japan, the company spent the last 75 years growing its business from mass-producing piston rings and surplus engines to becoming the automotive powerhouse it now is. Today, Honda continues to showcase its expertise through its contributions in artificial intelligence, aerospace, and automotive engineering fields.
Conclusion – 2007 Honda 400EX Review
The lack of mechanical and performance enhancements for the 2007 Sportrax was a huge disappointment for many of its ardent followers. Honda attempted to make amends for the upset by giving the quad another facelift and dropping the “E” in its designation the following year.
Unfortunately, these changes did not cut it (especially for mechanically savvy Sportrax owners), as people were looking for gains that went beyond superficial.
Despite having no substantial improvement, the ’07 Sportrax is still well-loved by the entire riding community. Its versatility is the platform nouveau riders need to learn the ropes of ATVing. It’s not as fast as the Arctic Cat DVX 400, but its low-end grunt and sturdiness are the best in its category and cannot be overlooked.
If you want an inexpensive sport quad with a solid track record and some game still in it, look no further than the 2007 Honda 400EX!
Kris is an avid off-roader and outdoor enthusiast who loves to brave the elements and take on challenging terrain. He also enjoys sharing his passion and knowledge with others so that they, too, can appreciate the ride.
About Kris