2023 Yamaha YZ125X Specifications

Name: 2023 Yamaha YZ125X
Brand: Yamaha

Enduro / Off-Road • Specs last verified 13 July 2026

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2023 Yamaha YZ125X Overview

For 2023, Yamaha offers the YZ125X as an enduro / off-road motorcycle with 125 cc on tap. The 2023 Yamaha YZ125X is built around a Single cylinder, two-stroke engine, a compression ratio of 10.2:1. Internally, bore and stroke are 54 x 54.5 mm. In everyday use, the 2023 YZ125X tips the scales at 96.2 kg, carries a 6.81-litre fuel tank, offers a seat height of 970 mm and spans a 1455 mm wheelbase. That's roughly 73.4 kg lighter than the average enduro / off-road motorcycle in our database. Every technical detail, from suspension travel to tyre sizes, is covered in the full 2023 Yamaha YZ125X spec sheet below.

2023 Yamaha YZ125X compared with other bikes in the Enduro / Off-Road category

Measured against other bikes in the Enduro / Off-Road category in our database (up to 1434 models, one entry per model), the 2023 Yamaha YZ125X comes out as follows.

With 970 mm, the YZ125X has the joint 43rd tallest seat height of 1146 bikes in the Enduro / Off-Road category, 10% above the category average of 879 mm.
Wet weight of 96.2 kg is lighter than that of 728 of the other 773 bikes in the Enduro / Off-Road category.
Only 189 of the other 1433 bikes in the Enduro / Off-Road category have a smaller engine displacement than the 125 cc of the YZ125X.
Narrowing the field to the 408 models within five model years of it, the seat height of 970 mm is taller than that of 405 of the other 407.

Versus the 2022 model

Compared with the 2022 model, wet weight went up from 94.8 kg to 96.2 kg (+1.4 kg) and seat height was lowered from 975 mm to 970 mm (-5 mm). Displacement is unchanged.

2023 YZ125X - 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.

Considerations

Carburetor fuelling: Carburetion is more hands-on than fuel injection - plan on periodic jetting and cleaning as part of routine ownership.
Tall seat height: A 970 mm seat puts flat-footing out of reach for a lot of riders - sit on it in person before committing.
Modest fuel capacity: A 6.81-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 YZ125X 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.

Brake disc and pad wear

Single disc with hydraulic 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 KYB® Speed-Sensitive System inverted fork; fully adjustable up front and KYB® single shock; fully adjustable 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 YZ125X means routine lubing and tension checks are part of ownership - skip them and sprocket wear accelerates noticeably.

Frame & chassis check

The Semi-double cradle aluminium 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 YZ125X's 96.2 kg kerb weight makes low-speed control noticeably less effort than on a heavier machine.

YZ125X - Buying & Maintenance Guide

What to check before buying

A pre-purchase check on the 2023 Yamaha YZ125X with its 125 cc enduro / off-road 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 3 years old, this enduro / off-road 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 YZ125X settles to a smooth idle within seconds.

Oil and filter changes

Oil changes are the cheapest insurance you can buy for the YZ125X's 125 cc single cylinder, two-stroke - keep to the manufacturer's interval rather than stretching it. The sump holds 0.70 litres, so budget for that volume of quality motorcycle-specific engine oil. With a 10.2:1 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 YZ125X 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.

2023 Yamaha YZ125X - Frequently Asked Questions

What engine does the 2023 Yamaha YZ125X have?

The 2023 Yamaha YZ125X uses a Single cylinder, two-stroke engine with 125 cc of displacement.

How much does the 2023 Yamaha YZ125X weigh?

The 2023 Yamaha YZ125X weighs 96.2 kg. This is the manufacturer's wet figure.

What is the fuel tank capacity of the 2023 Yamaha YZ125X?

The 2023 Yamaha YZ125X has a 6.81-litre fuel tank. At around 5-6 litres per 100 km, that is roughly 113-136 km between stops.

Is the 2023 Yamaha YZ125X suitable for shorter riders?

The 2023 Yamaha YZ125X has a seat height of 970 mm. This is towards the tall end of the spectrum and will require most riders under 175 cm to tiptoe at stops.

What brakes does the 2023 Yamaha YZ125X have?

The 2023 Yamaha YZ125X uses single disc with hydraulic at the front and single disc with hydraulic at the rear.

What tyre sizes does the 2023 Yamaha YZ125X use?

The front tyre size on the 2023 Yamaha YZ125X is 90/90-21.

How much oil does the 2023 Yamaha YZ125X take?

The 2023 Yamaha YZ125X takes 0.70 litres of engine oil at a full oil and filter change. Always verify against the dipstick or sight glass after filling.

Yamaha YZ125X Spec Evolution

The Yamaha YZ125X was produced across 5 model years (2017-2023). 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	2017	2020	2021	2022	2023
Wet Weight	93.5 kg / 206.1 lbs	94.8 kg / 209.0 lbs	94.8 kg / 209.0 lbs	94.8 kg / 209.0 lbs	96.2 kg / 212.0 lbs
Seat Height	-	975 mm / 38.4 in.	975 mm / 38.4 in.	975 mm / 38.4 in.	970 mm / 38.2 in.
Fuel Capacity	8.00 litres / 2.11 gallons	8.00 litres / 2.11 US gallons	8.00 litres / 2.11 US gallons	8.00 litres / 2.11 US gallons	6.81 litres / 1.80 US gallons
Displacement (cc)	124.00 cc	125.0 cc	125.0 cc	125.0 cc	125.0 cc
Displacement (ci)	7.57 cubic inches	7.63 cubic inches	7.63 cubic inches	7.63 cubic inches	7.63 cubic inches
Oil Capacity (Quarts)	0.05 quarts	0.74 US quarts	0.74 US quarts	0.74 US quarts	0.74 US quarts
Frame Type	Semi-double cradle aluminium frame	Semi-double cradle aluminium frame	Semi-double cradle aluminium frame	Semi-double cradle aluminium frame	Semi-double cradle aluminium
Wheelbase	1,443 mm / 56.8 in.	1455 mm / 57.3 in.	1455 mm / 57.3 in.	1455 mm / 57.3 in.	1455 mm / 57.3 in.

Key Specifications

Engine

Single cylinder, two-stroke

Power

Not recorded

Torque

Not recorded

Top Speed

Not recorded

Weight

96.2 kg / 212.0 lbs

Fuel Capacity

6.81 litres / 1.80 US gallons

Full 2023 Yamaha YZ125X Specifications

Colours Team Yamaha Blue

Warranty 30 Day Limited Factory Warranty

Ground Clearance (in.) 13.8 inches

Ground Clearance (mm) 351 mm

Seat Height 970 mm / 38.2 in.

Wheelbase 1455 mm / 57.3 in.

Height 1285 mm / 50.6 in.

Length 2141 mm / 84.3 in.

Width 825 mm / 32.5 in.

Oil Capacity (l) 0.70 litres

Oil Capacity (Quarts) 0.74 US quarts

Fuel Capacity 6.81 litres / 1.80 US gallons

Wet Weight 96.2 kg / 212.0 lbs

Bore x Stroke (in,) 2.1 x 2.1 inches

Bore x Stroke (mm) 54.0 x 54.5 mm

Displacement (cc) 125.0 cc

Displacement (ci) 7.63 cubic inches

Engine Type Single cylinder, two-stroke

Engine Detail Reed-valve-inducted

Fuel System Carburettor. Hitachi Astemo® Keihin PWK38S

Compression Ratio 10.2:1

Engine Lubrication Premix

Ignition CDI

Starter Kick

Clutch O-ring chain

Final Drive Chain (final drive)

Gearbox 6-speed

Frame Type Semi-double cradle aluminium

Suspension - Front KYB® Speed-Sensitive System inverted fork; fully adjustable

Suspension - Rear KYB® single shock; fully adjustable

Rake 26.8°

Trail 117 mm / 4.6 in.

Wheel Travel - Front 300 mm / 11.8 in.

Wheel Travel - Rear 315 mm / 12.4 in.

Brakes - Front Single disc. Hydraulic.

Brakes - Rear Single disc. Hydraulic.

Rims Dunlop® Geomax MX33 tires

Tyres - Front 90/90-21

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