KTM 65 SX [2011-2016]: A Youth Motocross Legend Tested

Introduction

The KTM 65 SX, produced from 2011 to 2016, is a motorcycle that needs no introduction in the world of youth motocross. Designed for young riders aged 8–12 transitioning from smaller minibikes, this 65cc two-stroke machine has earned a reputation as a fierce competitor on the track and a reliable training tool for aspiring racers. With its orange-and-black aesthetics, race-bred engineering, and a chassis that punches above its weight class, the 65 SX remains a benchmark in its category even years after its production run. Let’s dive into what makes this bike a standout choice for young riders and their parents.

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Design & Ergonomics: Built for Aggression, Sized for Youth

At first glance, the KTM 65 SX looks like a scaled-down version of KTM’s full-size race bikes—and that’s no accident. The aggressive styling, complete with angular plastics and bold graphics, gives it a “big bike” attitude. The seat height sits at 750 mm (29.5 inches), which is approachable for its target demographic but still tall enough to encourage proper riding posture.

The bike’s dry weight of 53–55.5 kg (116.8–122.4 lbs) makes it easy to maneuver, whether your young rider is whipping through berms or picking the bike up after a spill. The narrow central-tube chromoly steel frame keeps the center of gravity low, while the subframe (aluminum in later models) adds durability without bulk. Footpeg placement feels natural for standing attacks on jumps, and the handlebars offer a comfortable reach for smaller riders.

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Engine & Performance: Two-Stroke Fury, Refined Delivery

The heart of the KTM 65 SX is its 64.9cc liquid-cooled two-stroke engine, a powerhouse in miniature. With a bore x stroke of 45.0 x 40.8 mm (1.8 x 1.6 in), this single-cylinder mill delivers a thrilling top speed of 80.5 km/h (50 mph)—enough to keep young adrenaline junkies hooked but not overwhelming for developing skills.

Key Highlights:

• Carburetion: Earlier models used a Mikuni TM 24 carburetor, providing crisp throttle response. Jetting adjustments are straightforward for altitude or temperature changes.
• 6-Speed Gearbox: Rare in the 65cc class, the close-ratio transmission lets riders maintain momentum through technical sections. Shifts are precise, though the clutch (hydraulically operated from 2012 onward) requires a firm pull for smaller hands.
• Powerband: The reed-valve-controlled intake ensures a broad power delivery. Low-end torque is manageable, but the real fun begins when the revs climb and the exhaust note sharpens into a metallic scream.

Parents will appreciate the liquid cooling system, which prevents overheating during long motos or slow technical drills. The kickstarter is reliable, though teaching proper technique is essential—this isn’t a bike that tolerates half-hearted jabs.

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Chassis & Suspension: WP Components for Pro-Level Handling

KTM’s partnership with WP Suspension shines here. Later models (2013–2016) feature a WP USD 35 mm front fork with 215 mm (8.5 in) of travel and a WP 3614 BAVP rear shock offering 270 mm (10.6 in) of rear wheel movement. Even at speed through choppy whoops, the suspension stays composed, absorbing impacts without wallowing.

The 25.5° rake angle and 1,137 mm (44.8 in) wheelbase strike a balance between stability and agility. Cornering is razor-sharp, and the bike flicks sideways effortlessly mid-air. Earlier models (2011–2012) used Marzocchi forks with slightly less adjustability, but they’re still capable for casual racing.

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Brakes & Wheels: Confidence-Inspiring Stoppers

The KTM 65 SX surprises with its braking prowess. Front brakes use a single 160 mm wave disc gripped by a four-piston caliper, while the rear employs a two-piston setup. Bite is strong but progressive—ideal for teaching modulation.

Tire sizes (60/100-14 front, 80/100-12 rear) provide ample grip on hardpack, though many riders upgrade to softer compounds for muddy conditions. The aluminum rims withstand hard landings, and the 280 mm (11 in) ground clearance ensures minimal peg-dragging through ruts.

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Competition: How the KTM 65 SX Stacks Up

The 65cc class is fiercely competitive. Here’s how the KTM holds its ground:

1. Kawasaki KX65

• Pros: Softer power delivery for beginners, lower seat height.
• Cons: 5-speed gearbox, air-cooled engine (overheats under stress).
• KTM Edge: Liquid cooling, hydraulic clutch (2012+), and superior suspension.

2. Husqvarna TC 50

• Pros: Electric start, lighter weight.
• Cons: Smaller engine displacement, less suited for advanced riders.
• KTM Edge: Larger 65cc engine, race-focused ergonomics.

3. Cobra CX65

• Pros: Race-ready out of the crate, potent engine.
• Cons: High maintenance demands, niche parts availability.
• KTM Edge: More durable for recreational use, widespread aftermarket support.

The KTM’s 6-speed transmission and hydraulic clutch (post-2011 models) give it a technical edge, while its parts ecosystem (thanks to KTM’s racing pedigree) makes long-term ownership practical.

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Maintenance: Keeping the 65 SX in Peak Condition

Owning a KTM 65 SX means embracing its race-oriented DNA—which includes regular upkeep. Here’s your cheat sheet:

1. Engine & Transmission

• Oil: Use SAE 15W-50. Change every 15–20 hours.
• Fuel Mix: 1:60 premix ratio. Opt for high-octane fuel to prevent detonation.
• Spark Plug: Replace LR8B plugs every 10–15 hours.

2. Chassis & Drivetrain

• Chain: Clean and lubricate the 420-size chain after every ride. Adjust tension to 25–35 mm (1–1.4 in) of free play.
• Sprockets: The 14/48 tooth combo wears quickly in sandy conditions. Inspect monthly.

3. Suspension & Brakes

• Fork Seals: Clean with a plastic seal saver tool to prevent leaks.
• Brake Fluid: Replace DOT 4/5.1 fluid annually to maintain lever feel.

MOTOPARTS.store Recommendations:

• Upgrade to a heavy-duty chain for longer lifespan.
• Swap stock brake pads for sintered metal versions in muddy environments.
• Consider a skid plate to protect the engine during trail adventures.

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Final Thoughts: A Bike That Builds Champions

The KTM 65 SX isn’t just a motorcycle—it’s a rite of passage. For young riders, mastering its powerband and suspension teaches critical skills that translate to larger bikes. Parents will value its durability and the wealth of aftermarket upgrades available (hint: MOTOPARTS.store has you covered). While it demands respect and maintenance, few bikes in its class deliver such a perfect blend of excitement and engineering.

Whether your child is lining up at the starting gate or carving backyard trails, the 2011–2016 KTM 65 SX remains a worthy steed. Keep the premix fresh, the tires muddy, and let the good times rip.

Stay tuned to MOTOPARTS.store for expert guides, OEM replacements, and performance upgrades to keep your KTM 65 SX dominating the track.

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Specifications sheet

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