Do you have a teen interested in motocross racing? Looking for a motorcycle that’s powerful but ideal for beginners? Well, you’ve come to the right place. In this guide, you’ll learn what a Yamaha YZ125 is, its features and specs, how fast it can go, how to increase its top speed, and much more.

A Brief Overview Of Yamaha YZ125

The Yamaha YZ125 racing motorcycle is competitive on any track. Built by Yamaha in 1974, the latest bike comes with an advanced and liquid-cooled 125cc two-string engine with a peak horsepower of 34.44. Compared to the previous model, the latest produces more horsepower thanks to the powerful engine.

Yamaha’s pursuit to build a better and faster racing bike led to the decision of using a lightweight fine tuned chassis. The rider-friendly chassis provides more control, and helps you handle the bike better. It also ensures you experience lesser rider fatigue. As such, it’s the ideal racing motorcycle for advanced riders looking to win races and gain confidence.

Besides a lightweight chassis, Yamaha chose an ergonomic design. Unlike the previous models, Yamaha went for a flatter seat, smoothly integrated body panes, and a narrow fuel tank. All these upgrades allow the rider to have greater freedom of movement forward and back. How you may ask. The rider can shift his body weight for increased confidence and control.

Yamaha YZ125 Specs and Features:

The followings are the specs and features of the YZ125:

Powerful Two-stroke Engine

The Yamaha YZ125 comes with a liquid-cooled engine capable of displacing 125cc. To ensure the two-stroke engine delivers more torque and maintains the heat, Yamaha chose liquid cooling. This ensures that the engine does not overheat at high RPMs which allows you to accelerate even better.

In fact, once you get to the mid-range, that is when you unleash the bike’s inner beast. As you hit the power band, it might be scary at first but you’ll understand why riding the bike is addictive.

Ergonomic Design

While the 125cc engine can provide lots of torque allowing you to accelerate faster and better, the design of the bike plays a critical role. To ensure riders can win races and achieve faster lap times, Yamaha went with an ergonomic design for the YZ125.

They incorporated smoothly integrated body panels and installed a narrow fuel tank and a flatter seat. Thanks to these upgrades, reduced the weight of the bike significantly which makes it accelerate faster.

Lightweight Chassis

As aforementioned, the bike comes with a rider-friendly chassis. Built with lightweight materials, the bike provides nimble handling and control. This is essential for taking corners and making other moves.

In addition, the lightweight chassis provides a better platform for riders which ensures less fatigue. As you already know, fatigue can reduce your concentration, energy, and overall mindset. If you want to win, you need a bike that ensures less fatigue.

Industry-leading Fork

KYB’s industry-leading fork offers unmatched capability, control, and comfort. The 48 mm inverted front fork and the fully adjustable rear shock work together to ensure better handling and control when racing.

The front fork includes a leaf spring in the mid-speed valve that ensures increased comfort and performance. For the adjustable rear shock, it comes with reduced friction coat internals and a full lock oil rebound system for better control.

High-performance Braking System

When it comes to safety, the brakes and the tires are among the most important elements of a racing bike. To ensure the rider’s safety, Yamaha YZ125 comes with a 270 mm front rotor and 240 mm rear rotor. It also includes rigid calipers and large front pistons. When combined, all these features provide exceptional braking power which every rider needs.

Aluminum Handlebar

Made from aluminum alloy, the YZ125 handlebar provides a mounting place for accessories. They include the clutch, brake, throttle, light switches, horn, and rearview mirrors. 

Besides supporting the above accessories, the handlebar also supports part of the rider’s weight.

Yamaha YZ125 Top Speed

Over the years, Yamaha has upgraded and improved the YZ125’s performance and design. Thanks to these upgrades, the motorcycle now accelerates faster than other models. However, the top speed varies between models.

For example, the 2019 YZ125 has a top speed of 60 MPH which is similar to the top speed of a 2000 YZ125. From this comparison, we can see that the speed of the YZ125 remained unchanged for two decades.

However, things started to change in 2022. Yamaha incorporated new upgrades such as a flatter seat and narrower fuel tank. These upgrades reduced the weight of the Yamaha YZ125 allowing it to reach up to 65 to 70 miles per hour.

In fact, the 2022 and 2023 models can achieve a top speed of around 70 miles per hour (112 kmh).

Using its two-stroke 125 cc engine, the Yamaha YZ125 moves like a speed demon on the track leaving your opponents in the dust.

How to Increase the Yamaha YZ125’s Top Speed?

The maximum speed you can get out of a 2022 or 2023 Yamaha YZ125 is 70 MPH (112 KMH). While this beast can leave your opponents in the dust, some mods can help you increase its speed past 70 MPH (112 KMH).

Add 10 more horsepower to your Yamaha YZ125 by installing the VForce 3 reeds. The unique design of the valve system offers an increased bottom end plus a stronger mid-range and longer top end. It also allows more air into the system providing more horsepower.

Another mod that will increase the speed of your YZ125 is gearing. Going to a 13/49 from a 13/48 is a better choice for your two-stroke YZ125. The gearing system allows you to shift between gears faster.

All you need to do is change the front and rear sprocket. If you change the 14-tooth front sprocket with a 6-foot front sprocket, you’ll have a higher top speed. Also, if you go for a smaller rear sprocket, the top speed will increase too.

Lastly, we have the 144cc Big Bore Cylinder kit that brings raw power and reliable performance. By installing the 144cc Big Bore cylinder kit, your YZ125 top speed will be higher thanks to the 16% increase in displacement.

Yamaha YZ125 – Pros and Cons:

Pros

• Super light
• Powerful two-stroke engine
• Well balanced
• Easy to maintain
• Fun to ride
• Excellent suspension

Cons

• Limited aftermarket products and support

Frequently Asked Questions

How fast is a stock YZ125?

The top speed of a stock 2022 or 2023 YZ125 is 70 mph (112 kmh) when you’re on flat ground. It comes with a two-stroke engine but it’s faster than models with a four-stroke engine.

What age should I ride a 125?

You can ride the YZ125 when you’re 12 to 16 years of age and attained a height of 5 ft to 5ft 8 inches. You’ll also enjoy riding the YZ125 if you’re an adult of any age and like to have fun on a small-bore two-stroke.

Final Thoughts

Despite having a two-stroke engine, the Yamaha YZ125 is a beast. As a great all-around bike, it’s ideal for teens and adults who want to have a fun ride. Although it’s powerful, the bike is easy to ride, control, and maintain. Good for trail riding, it’s ideal for racers and riders exploring the woods.