The Gas Gas TXT 300 (2003-2014): A Trials Machine That Rewrites the Rules of Agility

Introduction

The Gas Gas TXT 300 isn’t just a motorcycle—it’s a precision instrument for conquering impossible terrain. From 2003 to 2014, this Spanish-built trials bike carved its name into the sport’s history with a blend of featherweight construction, explosive two-stroke power, and a chassis that feels like an extension of the rider’s body. After spending hours threading it through rocky gullies, balancing on near-vertical climbs, and bouncing off fallen logs, one thing becomes clear: the TXT 300 isn’t designed to play by the rules. It exists to rewrite them.

Let’s dissect why this generation remains a benchmark for trials enthusiasts and a platform begging for personalization through aftermarket upgrades.

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The Heartbeat: A 294cc Two-Stroke That Thrives on Chaos

At the core of the TXT 300 lies a liquid-cooled 294cc single-cylinder two-stroke engine. With a bore and stroke of 79mm x 60mm (3.1” x 2.4”), this isn’t a motor built for straight-line speed—it’s about instantaneous torque and throttle response so sharp it feels telepathic.

Key Characteristics:
- Carburetion Evolution: Early models used Dell’Orto PHBHL 26BS carbs, while later years swapped to Keihin PWK 28 setups. The Keihin’s crisper fuel delivery shines in technical sections where millimeter-perfect throttle control matters.
- Powerband Sorcery: The CDI ignition system ensures a smooth, linear power delivery at low RPMs, transitioning to a violent mid-range punch that launches the bike upward. Yet it never feels unruly—a rarity in pre-EFI two-strokes.
- GG 4/6 Gearbox: Gas Gas’s patented gearbox (6-speed with a “4/6” ratio spread) is a masterstroke. First gear crawls at walking pace for balance sections, while sixth still lets you connect trails without screaming the engine.

Riding the TXT 300 feels like conducting an orchestra of controlled explosions. The engine’s 2.5% oil mixture requirement (1:50 ratio) keeps smoke minimal, but that signature two-stroke aroma is ever-present—a perfume for purists.

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Chassis and Handling: Where Physics Takes a Backseat

Weight Distribution:
At 66–69 kg (145–152 lbs) dry, the TXT 300’s weight isn’t just low—it’s centralized. The CrMo (chromoly) frame, with its elliptical tubing and magnesium components in later Raga editions, places the engine mass close to the rider’s knees. This makes pivoting mid-obstacle feel instinctive.

Ergonomics:
- Seat Height: Ranging from 635–665 mm (25–26.2”), the low saddle lets you dab a foot effortlessly. It’s a standing bike 95% of the time, but when you do sit, it’s like perching on a narrow bench—trials bikes aren’t meant for comfort.
- Wheelbase: 1,320–1,340 mm (52–52.8”) keeps the bike compact, aiding tight turns.

Tires and Wheels:
- Front: 2.75-21” tires bite into loose soil and grip wet rocks.
- Rear: 4.00-18” provides enough squirm for controlled slides.

The aluminum spoke rims (post-2008) shave rotational mass, making the bike flickable. On loose gravel or moss-covered stones, the TXT 300 feels like it’s reading the terrain ahead.

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Suspension and Brakes: Precision Over Plushness

Front Suspension:
Marzocchi’s 40mm “Right-Sight-Up” forks (2006 onward) dominate here. With 177mm (7”) of travel, they’re stiffly sprung for sharp impacts—think jagged rocks, not desert whoops. Adjustable compression and rebound (later models) let you tune out kickback on downhill hops.

Rear Suspension:
A progressive linkage system pairs with shocks from Öhlins, Sachs, or Reiger. The 164mm (6.5”) travel is modest, but the rising-rate design soaks up square-edged hits. Preload and rebound adjustments (post-2010) help balance the bike for riders weighing 60–90 kg (132–198 lbs).

Brakes:
- Front: A 150mm single disc with a 4-piston caliper (floating rotor on Racing models) offers surgical stopping power.
- Rear: 2-piston caliper modulates slides without locking.

These aren’t brakes—they’re pressure-sensitive triggers. One-finger control is enough to halt the bike mid-ledge.

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Competition: How the TXT 300 Stacks Up

The trials world revolves around three rivals: Beta Evo 300, Sherco 300 SE, and Montesa Cota 4RT. Here’s where the Gas Gas shines (and stumbles):

| Aspect | Gas Gas TXT 300 | Beta Evo 300 | Sherco 300 SE | |----------------------|----------------------------------------------|---------------------------------------|----------------------------------------| | Engine | Raw, aggressive two-stroke | Smoother power delivery | EFI-equipped (post-2014), linear | | Weight | 66–69 kg (145–152 lbs) | ~67 kg (148 lbs) | ~68 kg (150 lbs) | | Clutch | Hydraulic diaphragm (buttery modulation) | Cable-operated (more feedback) | Hydraulic (similar to Gas Gas) | | Aftermarket | Huge parts variety (MOTOPARTS.store stocks!) | Growing community support | Limited vs. Gas Gas | | Weakness | Carb tuning required for altitude | Less “explosive” personality | Higher seat (660mm/26”) |

The TXT 300’s edge? Customization. Few bikes accept aftermarket upgrades as readily—whether it’s a S3 head for smoother power or a Domino throttle for quicker response.

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Maintenance: Keeping the Spanish Legend Alive

Critical Service Points:
1. Air Filter: Clean every 10 hours. Use biodegradable oil—dust is the TXT 300’s nemesis.
2. Carb Jets: Swap jets for altitude changes. Keihin PWK 28 pilots clog faster than Dell’Ortos.
3. Clutch Fluid: Mineral oil (LHM+ compatible) yearly. Avoid DOT fluid to preserve seals.
4. Suspension Linkage: Grease every 30 hours. Saltwater or mud accelerates wear.
5. Exhaust Valve: decarbonize every 50 hours. Sticky valves blunt the powerband.

Common Upgrades:
- V-Force Reeds: Sharpens throttle response.
- Lightweight Rotors: Galfer wave rotors shed 300g (0.66 lbs).
- Adjustable Triple Clamps: Fine-tune fork angle for technical terrain.

Pro Tip: The hydraulic clutch’s “1/3” diaphragm design (1 steel disc, 3 fibers) wears unevenly. Replace fibers as a set, even if one seems intact.

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Conclusion: A Bike That Demands Creativity

The Gas Gas TXT 300 isn’t just a relic—it’s a canvas. Whether you’re resurrecting a 2004 carbureted model or fine-tuning a 2014 Racing edition, this bike thrives on personalization. Its lightweight frame and explosive engine make it a trials icon, while its quirks (like jetting headaches) endear it to tinkerers.

At MOTOPARTS.store, we’ve ridden, rebuilt, and reimagined countless TXT 300s. From upgraded shock springs to titanium footpegs, every modification unlocks new potential. Because with a Gas Gas, the only limit is your imagination—and maybe gravity.

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Specifications sheet

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