Gas Gas 400 FSE (2000-2004): A Forgotten Supermoto Gem That Deserves Your Attention

Introduction

The early 2000s were a golden era for niche European motorcycles experimenting with cutting-edge technology. Among these hidden treasures sits the Gas Gas 400 FSE - a Spanish supermoto that blended enduro DNA with street-smart agility. While often overshadowed by Austrian rivals, this liquid-cooled single-cylinder machine deserves recognition as one of the most intriguing "what if?" stories in motorcycling history. Let's explore why this 260-lb (118 kg) underdog still puts grins on riders' faces two decades later.

Riding Experience: Where Playfulness Meets Precision

Swinging a leg over the 35.4-inch (900 mm) seat reveals a cockpit designed for action. The narrow chassis melts beneath you, creating an immediate connection that modern bikes often engineer out of existence. Thumb the electric starter (a luxury in this era), and the fuel-injected 399cc single awakens with a purposeful thrum - no carbureted hiccups here.

In urban environments, the 400 FSE transforms concrete jungles into playgrounds. The 17-inch wheels (120/60 front, 150/60 rear) provide just enough leverage for knee-down antics, while the 58.1-inch (1,475 mm) wheelbase keeps things lively without becoming twitchy. Dart between traffic with the confidence of a trials rider, the Öhlins rear shock swallowing potholes that would unsettle lesser supermotos.

Venture onto backroads, and the character shifts. The 47 hp (35 kW) powerplant thrives on momentum, building steam from 6,500 RPM like a steam locomotive hitting its stride. While not a top-speed monster (expect about 90 mph/145 kmh), the real magic lives between 30-70 mph (48-113 kmh) where the combination of 31.7 lb-ft (43 Nm) torque and 118 kg (260 lbs) dry weight creates explosive overtakes.

Engine Performance: Ahead of Its Time

Gas Gas made a bold move equipping this generation with Magneti Marelli fuel injection - technology Japanese manufacturers wouldn't widely adopt until years later. The result? Throttle response that shames carbureted contemporaries. Crack the wrist at any RPM, and the single-cylinder answers without bog or hesitation.

The 90x62.6 mm bore/stroke ratio leans toward rev-happy characteristics, but clever tuning gives this engine split personalities: - Below 6,000 RPM: Tractor-like lugging ability perfect for technical terrain - 6,000-9,000 RPM: A surging midrange that pulls through corners - 9,000+ RPM: A screaming top-end that rewards aggressive riders

Liquid cooling keeps temperatures in check during extended abuse, though the small 2.0-gallon (7.5L) fuel tank reminds you this isn't a continent-crosser. Expect 50-60 mpg (4.7-3.9 L/100km) during spirited riding - decent range for a supermoto, but plan fuel stops on longer adventures.

Handling & Suspension: Trials Heritage Meets Track Potential

The chromoly frame and aluminum swingarm form a chassis that's stiff yet communicative. At low speeds, the 400 FSE flicks side-to-side like a trials bike - a nod to Gas Gas' off-road roots. Push harder, and the geometry reveals its supermoto intent with planted cornering and minimal flex.

Marzocchi's 45mm forks (11.6 in/295 mm travel) and the Öhlins shock (12.6 in/320 mm) create a plush yet controlled ride. Out-of-the-box settings favor technical terrain over track use: - Front: Slightly soft initial stroke absorbs urban imperfections - Mid-stroke: Progressive damping controls weight transfer during hard braking - Rear: Excellent squat control prevents bottoming on big hits

Aggressive riders will want to stiffen compression damping, particularly when attacking curvy tarmac. The 11.4-inch (290 mm) ground clearance allows serious lean angles before peg feelers touch down - a confidence booster when exploring the limits.

Brakes & Wheels: Adequate With Upgrade Potential

The single 260mm front disc (310mm on later models) with 2-piston caliper provides decent stopping power for a bike this light. During testing, the setup proved: - Initial bite: Progressive rather than abrupt - Mid-corner modulation: Excellent lever feedback - High-speed stability: Fades slightly during repeated hard use

This is where MOTOPARTS.store can transform the experience. Swapping to: - Braided steel lines (improves lever feel) - High-performance pads (reduces fade) - Larger rotor kits (increases stopping power)

...turns adequate brakes into track-ready weapons. The stock 150/60-17 rear tire offers surprising grip, but modern rubber like Michelin Power Supermoto transforms corner speed.

Competition: How It Stacks Up

The 400 FSE existed in a crowded arena. Here's how it compared to key rivals:

1. KTM 400 EXC (2000-2003)
- Pros: Lighter (249 lbs/113 kg), stronger aftermarket
- Cons: Carbureted engine, harsh suspension
- Verdict: The KTM wins in parts availability, but the Gas Gas' fuel injection gives it an edge in rideability

2. Husqvarna TE 410 (2001-2004)
- Pros: Raw power (53 hp), iconic styling
- Cons: Vibration issues, cramped ergonomics
- Verdict: The Husky feels more "race ready" but less polished day-to-day

3. Yamaha WR400F (1998-2000)
- Pros: Bulletproof reliability, tunable engine
- Cons: Heavy (262 lbs/119 kg), dated technology
- Verdict: Yamaha's tank-like durability vs Gas Gas' tech - choose your priority

Where the 400 FSE Shines:
- Cutting-edge fuel injection in an era of carbs
- Öhlins suspension outclasses WP/KYB equivalents
- Narrower profile enhances flickability

Maintenance: Keeping the Spanish Stallion Healthy

As a MOTOPARTS.store journalist, I've seen these bikes age gracefully with proper care. Key considerations:

1. Oil Changes
- Frequency: Every 15 hrs off-road / 500 mi (800 km) street
- Recommendation: Use JASO MA2 10W-50 synthetic
- Pro Tip: Install a magnetic drain plug to catch metal particulates

2. Air Filter Service
- Challenge: Cramped airbox design
- Solution: Upgrade to twin-air foam filter with pre-oiled skins
- Interval: Clean every 10 hrs/300 mi (480 km)

3. Suspension Refresh
- Front Forks: Replace bushings every 200 hrs, use SKF seals
- Rear Shock: Rebuild Öhlins unit annually for plush performance

4. Electrical Upgrades
- Common Issue: Weak stator output
- Fix: Install high-output stator kit for accessory lights
- Bonus: LED headlight conversions reduce load

5. Chain & Sprockets
- Stock: 520 pitch wears quickly
- Upgrade: DID ERV3 chain + supersprox stealth sprockets
- Gearing: +1 tooth rear for better street manners

Conclusion: An Overlooked Masterpiece

The Gas Gas 400 FSE represents a fascinating crossroads in motorcycle history - too advanced for its time, yet too niche for mainstream success. What remains is a machine that rewards skilled riders with telepathic handling and an engine character no modern bike can replicate.

While newer supermotos offer ABS and ride modes, they often lack the raw mechanical connection that makes the 400 FSE special. With sensible upgrades from MOTOPARTS.store - better brakes, fresh suspension components, quality filters - this Spanish warrior transforms into a modern classic ready for another decade of backroad domination.

For riders craving individuality without sacrificing performance, the 400 FSE isn't just a motorcycle - it's a statement against automotive homogenization. And isn't that what motorcycling's all about?

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Specifications sheet

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