2020 Yamaha YZ125 Specifications

Name: 2020 Yamaha YZ125
Brand: Yamaha

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2020 Yamaha YZ125 Overview

The 2020 Yamaha YZ125 is a cross / motocross motorcycle built around 125 cc of displacement. Under the tank sits a Single cylinder, two-stroke engine, a compression ratio of 10.7:1. The bore and stroke measures 54 x 54.5 mm. From a practical standpoint, the 2020 YZ125 tips the scales at 93.9 kg, carries a 8-litre fuel tank, offers a seat height of 975 mm and spans a 1443 mm wheelbase. Scroll down for the complete 2020 Yamaha YZ125 spec sheet covering every technical detail from suspension travel to tyre sizes.

2020 YZ125 - Pros & Cons

Strengths

Factory engineering: The 2020 Yamaha YZ125 represents Yamaha's engineering at the time, with a specification built around real-world usability.

Considerations

Carburetor fuelling: Carbureted engines need occasional jetting attention and can be reluctant in cold weather or at altitude compared to modern fuel-injected alternatives.
Tall seat height: The 975 mm seat height will challenge shorter riders - tiptoeing at low speeds is something to factor into your decision.

Owner Experiences & Common Issues

Carburetor maintenance

Carburetors on the 2020 Yamaha YZ125 benefit from a clean and re-jet if the bike has been stored, run on stale fuel, or modified with an aftermarket exhaust. Owners frequently mention that fresh jets and float needle clips transforms throttle response from flat to crisp.

YZ125 - Buying & Maintenance Guide

What to check before buying

When inspecting a used 2020 Yamaha YZ125, start with the basics: check the service book for oil change frequency, inspect the chain and sprockets for wear, and look for oil seepage around the engine casings and rocker covers. A cold start test is invaluable - a well-maintained YZ125 should fire up cleanly and settle to a smooth idle within a few seconds.

Oil and filter changes

Regular oil changes are the single most important maintenance task on any YZ125. Stick to the manufacturer's interval - typically every 6,000 km or once a year, whichever comes first. The sump holds 0.70 litres, so budget for that volume of quality motorcycle-specific engine oil. Always use the correct viscosity grade as specified in the owner's manual.

Carburetor upkeep

Keep the carburetors clean and free of deposits. If the YZ125 has been stored, strip and clean the carb float bowls before attempting to start it. Pilot jets are the first to block and the last to be checked - always include them in any carb rebuild.

2020 Yamaha YZ125 - Frequently Asked Questions

What engine does the 2020 Yamaha YZ125 have?

The 2020 Yamaha YZ125 uses a Single cylinder, two-stroke engine with 125 cc of displacement.

How much does the 2020 Yamaha YZ125 weigh?

The 2020 Yamaha YZ125 weighs 93.9 kg. This is the manufacturer's wet figure.

What is the fuel tank capacity of the 2020 Yamaha YZ125?

The 2020 Yamaha YZ125 has a 8-litre fuel tank.

Is the 2020 Yamaha YZ125 suitable for shorter riders?

The 2020 Yamaha YZ125 has a seat height of 975 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 2020 Yamaha YZ125 have?

The 2020 Yamaha YZ125 uses Single disc. Hydraulic. at the front and Single disc. Hydraulic. at the rear.

What tyre sizes does the 2020 Yamaha YZ125 use?

The front tyre size on the 2020 Yamaha YZ125 is 80/100-21.

How much oil does the 2020 Yamaha YZ125 take?

The 2020 Yamaha YZ125 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 YZ125 Spec Evolution

The Yamaha YZ125 was produced across 21 model years (2002-2023). 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	2002	2004	2005	2006	2007	2008	2009	2010	2011	2012	2013	2014	2015	2016	2017	2018	2019	2020	2021	2022	2023
Wet Weight	-	-	-	-	-	-	94.3 kg / 208.0 lbs	94.3 kg / 208.0 lbs	94.4 kg / 208.0 lbs	94.4 kg / 208.0 lbs	93.9 kg / 207.0 lbs	93.9 kg / 207.0 lbs	94.8 kg / 209.0 lbs	94.8 kg / 209.0 lbs	94.8 kg / 209.0 lbs	93.9 kg / 207.0 lbs	93.9 kg / 207.0 lbs	93.9 kg / 207.0 lbs	93.9 kg / 207.0 lbs	94.8 kg / 209.0 lbs	94.8 kg / 209.0 lbs
Dry Weight	87.5 kg / 192.9 lbs	87 kg / 191.8 lbs	-	86 kg / 189.6 lbs	86.2 kg / 190.0 lbs	86.2 kg / 190.0 lbs	-	-	-	-	210.5 kg / 464.1 lbs	59 kg / 130.1 lbs	-	-	-	-	-	-	-	-	-
Engine Detail	-	-	-	-	-	-	-	-	-	Reed-valve inducted	Reed-valve-inducted	Reed-valve-inducted	Reed-valve-inducted	Reed-valve-inducted	Reed-valve-inducted	Reed-valve-inducted	Reed-valve-inducted	Reed-valve-inducted	Reed-valve-inducted	Reed-valve-inducted	Reed-valve-inducted
Engine Type	Single cylinder	Single cylinder	Single cylinder	V2	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	Single cylinder, two-stroke
Top Speed	-	-	-	-	-	-	-	-	-	-	-	120.0 km/h / 74.6 mph	-	-	-	-	96.0 km/h / 59.7 mph	-	-	-	-
Seat Height	994 mm / 39.1 in.	992 mm / 39.1 in.	993 mm / 39.1 in.	998 mm / 39.3 in.	998 mm / 39.3 in.	998 mm / 39.3 in.	998 mm / 39.3 in.	998 mm / 39.3 in.	998 mm / 39.3 in.	998 mm / 39.3 in.	998 mm / 39.3 in.	998 mm / 39.3 in.	975 mm / 38.4 in.	975 mm / 38.4 in.	975 mm / 38.4 in.	975 mm / 38.4 in.	975 mm / 38.4 in.	975 mm / 38.4 in.	975 mm / 38.4 in.	39 mm / 1.5 in.	980 mm / 38.6 in.
Fuel Capacity	-	-	7.94 litres / 2.10 gallons	8.00 litres / 2.11 gallons	7.94 litres / 2.10 gallons	7.94 litres / 2.10 gallons	7.94 litres / 2.10 gallons	7.94 litres / 2.10 gallons	7.95 litres / 2.10 gallons	7.95 litres / 2.10 gallons	7.95 litres / 2.10 gallons	7.95 litres / 2.10 gallons	7.95 litres / 2.10 gallons	7.95 litres / 2.10 gallons	8.00 litres / 2.11 gallons	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	6.81 litres / 1.80 US gallons
Oil Capacity (Quarts)	-	-	-	-	-	-	-	-	0.05 quarts	-	-	-	-	-	0.05 quarts	0.05 quarts	0.74 US quarts	0.74 US quarts	0.74 US quarts	0.74 US quarts	0.74 US quarts

Key Specifications

Engine

Single cylinder, two-stroke

Power

N/A

Torque

N/A

Top Speed

N/A

Weight

93.9 kg / 207.0 lbs

Fuel Capacity

8.00 litres / 2.11 US gallons

Full 2020 Yamaha YZ125 Specifications

Colours Team Yamaha Blue

Warranty 30 Day Limited Factory Warranty

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. Mikuni TMX 38

Compression Ratio 10.7:1

Engine Lubrication Premix

Ignition CDI

Starter Kick

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