2013 KTM 50 SX Specifications

Name: 2013 KTM 50 SX
Brand: KTM

Cross / motocross • Specs last verified 13 July 2026

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2013 KTM 50 SX Overview

For 2013, KTM offers the 50 SX as a cross / motocross motorcycle with 49 cc on tap. The 2013 KTM 50 SX is built around a Single cylinder, two-stroke engine running Single Overhead Cams (SOHC) valve actuation, a compression ratio of 10.6:1. Internally, bore and stroke are 39.5 x 40 mm. Out on the road, the 50 SX delivers 9.20 Nm @ 7000 Revolutions of torque. In everyday use, the 2013 50 SX tips the scales at 41.5 kg, carries a 2.30-litre fuel tank, offers a seat height of 684 mm and spans a 1,032 mm wheelbase. Every technical detail, from suspension travel to tyre sizes, is covered in the full 2013 KTM 50 SX spec sheet below.

2013 KTM 50 SX compared with other bikes in the Cross / motocross category

Measured against other bikes in the Cross / motocross category in our database (up to 224 models, one entry per model), the 2013 KTM 50 SX comes out as follows.

With 49 cc, the 50 SX has the joint smallest engine displacement of 224 bikes in the Cross / motocross category, 82% below the category average of 279 cc.
Seat height of 684 mm is lower than that of 191 of the other 199 bikes in the Cross / motocross category.
Only 5 of the other 58 bikes in the Cross / motocross category have a lower torque than the 9.2 Nm of the 50 SX.
Narrowing the field to the 93 models within five model years of it, the engine displacement of 49 cc is smaller than that of 90 of the other 92.

Versus the 2012 model

The figures we track are unchanged from the 2012 model: displacement and seat height all match.

2013 50 SX - Pros & Cons

Strengths

Strong front braking: The single disc front brake bites hard and stays consistent - a solid foundation whether it's stock or upgraded with braided lines.
Accessible seat height: At just 684 mm, flat-footing at a stop is easy for most riders - a genuine confidence builder for less experienced owners.

Considerations

Carburetor fuelling: Carburetion is more hands-on than fuel injection - plan on periodic jetting and cleaning as part of routine ownership.
Modest fuel capacity: A 2.30-litre tank keeps things light but means budgeting for more frequent fuel stops on any longer ride.
Chain final drive upkeep: A chain drivetrain is the most common setup in its class, but it's also the one that demands the most regular hands-on maintenance.

Wear Points & Servicing Notes

Carburetor maintenance

Being carbureted, the 50 SX is more sensitive to stale fuel and altitude changes than a fuel-injected bike - a carb clean and rejet restores crisp throttle response after any extended lay-up.

Valve clearance checks

Valve clearances on Single Overhead Cams (SOHC)-equipped engines like the 50 SX's drift slowly with mileage rather than failing suddenly - sticking to the service interval keeps it a non-issue.

Brake disc and pad wear

Single disc with four-piston calipers up front provides the primary stopping power; inspect disc thickness and pad wear at each tyre change to catch scoring before it becomes a rotor replacement.

Suspension condition on used examples

Suspension duties are handled by WP ?Suspension USD ?35 up front and WP ?Suspension ?3614 BAEM at the rear. Weeping fork seals aren't a dealbreaker on a used bike, but they're a fair basis for negotiating price.

Final drive maintenance

Chain final drive on the 50 SX means routine lubing and tension checks are part of ownership - skip them and sprocket wear accelerates noticeably.

Frame & chassis check

The Central tube frame of chrome molybdenum steel tubing, powder-coated chassis holds up well with normal use; on a used bike it's still worth checking the head-stock and swingarm pivot area for impact damage or corrosion.

Low-speed handling

The 50 SX's 41.5 kg kerb weight makes low-speed control noticeably less effort than on a heavier machine.

50 SX - Buying & Maintenance Guide

What to check before buying

A pre-purchase check on the 2013 KTM 50 SX with its 49 cc cross / motocross should cover the same ground every time: service history, drivetrain condition, and any oil seepage around the casings. This model runs chain final drive, so check chain slack and sprocket tooth profile specifically - a worn sprocket is a cheaper fix now than after it's chewed up the next chain. Now 13 years old, this cross / motocross is as likely to show age-related wear (perished rubber, seized fasteners, degraded seals) as mileage-related wear. Start it from cold if you can - a well-kept 50 SX settles to a smooth idle within seconds.

Oil and filter changes

Oil changes are the cheapest insurance you can buy for the 50 SX's 49 cc single cylinder, two-stroke - keep to the manufacturer's interval rather than stretching it. With a 10.6:1 compression ratio, running the octane grade specified in the manual matters more than on a lower-compression engine. Use the viscosity grade the manual specifies, not whatever's on sale.

Carburetor upkeep

A 50 SX that's sat unused is almost always a carb-cleaning job before it runs right again - float bowls and pilot jets first, since they clog before anything else.

Valve clearance service

There's no reliable seat-of-the-pants way to tell if a 50 SX's valve clearances are in spec - a light top-end tick is the only real warning sign, and by then some wear has already happened. Service records are the only proof.

2013 KTM 50 SX - Frequently Asked Questions

What engine does the 2013 KTM 50 SX have?

The 2013 KTM 50 SX uses a Single cylinder, two-stroke engine with 49 cc of displacement.

How much does the 2013 KTM 50 SX weigh?

The 2013 KTM 50 SX weighs 41.5 kg. This is the manufacturer's dry figure.

How much torque does the 2013 KTM 50 SX produce?

The 2013 KTM 50 SX produces 9.20 Nm @ 7000 Revolutions of torque.

What is the fuel tank capacity of the 2013 KTM 50 SX?

The 2013 KTM 50 SX has a 2.30-litre fuel tank. At around 5-6 litres per 100 km, that is roughly 38-45 km between stops.

Is the 2013 KTM 50 SX suitable for shorter riders?

The 2013 KTM 50 SX has a seat height of 684 mm. This is a comfortable, accessible height for most riders.

What brakes does the 2013 KTM 50 SX have?

The 2013 KTM 50 SX uses single disc with four-piston calipers at the front and single disc with two-piston calipers at the rear.

What tyre sizes does the 2013 KTM 50 SX use?

The 2013 KTM 50 SX runs 100/80-17 front and 110/80-17 rear tyres. A good selection of sport, touring and all-weather rubber is available in these sizes.

KTM 50 SX Spec Evolution

The KTM 50 SX was produced across 17 model years (2006-2023). The table below highlights the key specifications that changed across the production run - useful whether you are comparing years or tracking down a specific variant.

Specification	2006	2007	2008	2009	2010	2011	2012	2013	2014	2015	2016	2017	2018	2019	2021	2022	2023
Wet Weight	-	-	-	-	-	104.0 kg / 229.3 lbs	-	-	112.0 kg / 246.9 lbs	-	-	-	-	-	-	-	-
Dry Weight	38.8 kg / 85.5 lbs	38.8 kg / 85.5 lbs	38.8 kg / 85.5 lbs	39.8 kg / 87.7 lbs	39.8 kg / 87.7 lbs	39.8 kg / 87.7 lbs	41.5 kg / 91.5 lbs	41.5 kg / 91.5 lbs	39.8 kg / 87.7 lbs	39.8 kg / 87.7 lbs	41.5 kg / 91.5 lbs	41.5 kg / 91.5 lbs	41.5 kg / 91.5 lbs	41.5 kg / 91.5 lbs	41.5 kg / 91.5 lbs	41.5 kg / 91.5 lbs	41.5 kg / 91.5 lbs
Engine Detail	-	-	-	-	-	-	Reed intake	Reed intake.	Reed intake.	Reed intake.	Reed intake.	Reed intake.	Reed intake	Reed intake	-	-	-
Engine Type	Single cylinder	Single cylinder	Single cylinder	Single cylinder	Single cylinder, two-stroke	Single cylinder, two-stroke	Single cylinder, two-stroke	Single cylinder, two-stroke	Single cylinder, two-stroke	Single cylinder, two-stroke	Single cylinder, two-stroke	Single cylinder, two-stroke	Single cylinder, two-stroke	Single cylinder, two-stroke	Single cylinder, two-stroke	Single cylinder, two-stroke	Single cylinder, two-stroke
Seat Height	650 mm / 25.6 in.	650 mm / 25.6 in.	660 mm / 26.0 in.	684 mm / 26.9 in.	684 mm / 26.9 in.	684 mm / 26.9 in.	684 mm / 26.9 in.	684 mm / 26.9 in.	684 mm / 26.9 in.	684 mm / 26.9 in.	684 mm / 26.9 in.	684 mm / 26.9 in.	684 mm / 26.9 in.	684 mm / 26.9 in.	684 mm / 26.9 in.	665 mm / 26.2 in.	665 mm / 26.2 in.
Fuel Capacity	1.80 litres / 0.48 gallons	1.80 litres / 0.48 gallons	1.80 litres / 0.48 gallons	2.30 litres / 0.61 gallons	2.30 litres / 0.61 gallons	2.30 litres / 0.61 gallons	2.30 litres / 0.61 gallons	2.30 litres / 0.61 gallons	2.30 litres / 0.61 gallons	2.30 litres / 0.61 gallons	2.30 litres / 0.61 gallons	2.30 litres / 0.61 gallons	2.30 litres / 0.61 gallons	2.30 litres / 0.61 US gallons	2.30 litres / 0.61 US gallons	2.30 litres / 0.61 US gallons	2.30 litres / 0.61 US gallons
Stroke	2	2	2	2	-	-	-	-	-	-	-	-	-	-	-	-	2-stroke
Ground Clearance (mm)	255 mm	255 mm	255 mm	255 mm	252 mm	252 mm	252 mm	252 mm	252 mm	252 mm	252 mm	252 mm	252 mm	252 mm	252 mm	252 mm	252 mm

Key Specifications

Engine

Single cylinder, two-stroke

Power

Not recorded

Torque

9.20 Nm (0.9 kgf-m or 6.8 ft.lbs) @ 7000 Revolutions

Top Speed

Not recorded

Weight

41.5 kg / 91.5 lbs

Fuel Capacity

2.30 litres / 0.61 gallons

Full 2013 KTM 50 SX Specifications

Colours Orange/black

Ground Clearance (in.) 9.9 inches

Ground Clearance (mm) 252 mm

Seat Height 684 mm / 26.9 in.

Wheelbase 1,032 mm / 40.6 in.

Height 1,140 mm / 44.9 in.

Length 2,090 mm / 82.3 in.

Width 830 mm / 32.7 in.

Dry Weight 41.5 kg / 91.5 lbs

Fuel Capacity 2.30 litres / 0.61 gallons

Max Torque 9.20 Nm (0.9 kgf-m or 6.8 ft.lbs) @ 7000 Revolutions

Power-to-Weight Ratio 0.0815 HP/kg

Bore x Stroke (in,) 1.6 x 1.6 inches

Bore x Stroke (mm) 39.5 x 40.0 mm

Displacement (cc) 49.00 cc

Displacement (ci) 2.99 cubic inches

Engine Type Single cylinder, two-stroke

Fuel Control Single Overhead Cams (SOHC)

Engine Detail Reed intake.

Fuel System Carburettor

Compression Ratio 10.6:1

Engine Lubrication Mixture oil lubrication

Ignition SELETTRA 2p D36

Starter Kick

Valve System 2

Clutch 3-lining automatic clutch on the main shaft / centrifugal force

Final Drive Chain

Gearbox 5-speed

Primary Drive 11:40. Primary drive: 33:61 straight cut spur gear.

Frame Type Central tube frame of chrome molybdenum steel tubing, powder-coated

Suspension - Front WP ?Suspension USD ?35

Suspension - Rear WP ?Suspension ?3614 BAEM

Rake 24.0°

Wheel Travel - Front 205 mm / 8.1 in.

Wheel Travel - Rear 185 mm / 7.3 in.

Brakes - Front Diameter (in.) 6.3 inches

Brakes - Front Diameter (mm) 160 mm

Brakes - Rear Diameter (in.) 5.5 inches

Brakes - Rear Diameter (mm) 140 mm

Brakes - Front Single disc. Four-piston calipers.

Brakes - Rear Single disc. Two-piston calipers.

Tyres - Front 100/80-17

Tyres - Rear 110/80-17

Specifications are compiled from manufacturer documentation and cross-referenced technical sources, and corrected on an ongoing basis. Spot an error? Let us know.

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