Introduction

For motorcycle enthusiasts, especially fans of classic two-stroke bikes, the roar of the engine is a huge part of the experience. The exhaust system plays a critical role in shaping that sound, but its function goes far beyond acoustics. A well-designed exhaust can dramatically improve engine performance, efficiency, and overall rideability. One of the most iconic names in this world is the Yamaha RD series, and finding the right escapamento RD (RD exhaust) is key to unlocking its full potential.

Whether you’re restoring a vintage RD 135, tuning an RD 350 for the track, or simply looking to upgrade your bike’s performance, understanding the nuances of an escapamento RD is essential. This guide will walk you through the different types of exhaust systems, their impact on performance, and how to choose the perfect one for your motorcycle. We’ll cover everything from the classic original designs to modern performance-oriented options, helping you make an informed decision for your beloved two-stroke machine.

What Makes an RD Exhaust System Special?

The Yamaha RD series, particularly the RD 135 and RD 350, are legendary two-stroke motorcycles known for their impressive power-to-weight ratio and thrilling acceleration. The exhaust system on a two-stroke engine is not just a pipe to expel gases; it’s a finely tuned instrument that directly influences the engine’s power band.

Unlike four-stroke engines, two-strokes rely on the pressure waves created within the exhaust pipe to function efficiently. This phenomenon is known as the “expansion chamber.” A well-designed escapamento RD uses these pressure waves to help push the unburnt fuel-air mixture back into the cylinder and to help pull the burnt exhaust gases out. This process, known as scavenging, is crucial for maximizing power.

The shape, length, and volume of the expansion chamber are meticulously engineered to work best within a specific RPM range. This is why changing your escapamento RD can have such a profound effect on your bike’s character—it can shift the power band to be stronger at lower RPMs for city riding or optimize it for high-RPM power on a racetrack.

Types of Escapamento RD Available

When searching for a new exhaust for your Yamaha RD, you’ll encounter a few main categories. Each offers a different balance of performance, sound, and aesthetics.

Original Equipment Manufacturer (OEM) Exhausts

For restorers and purists, finding an original or OEM-style escapamento RD is the top priority. These exhausts are designed to replicate the factory specifications, delivering the performance and sound that Yamaha originally intended.

• Pros: Maintains the classic look and feel of the motorcycle. Ideal for vintage restorations and ensuring the bike remains period-correct.
• Cons: Can be difficult and expensive to find in good condition. Performance is generally milder compared to modern aftermarket options.

Performance Sport Exhausts

These are the most popular aftermarket options for riders looking to boost their bike’s power. Performance exhausts are engineered with optimized expansion chambers to improve horsepower and torque. They often come in different styles, from high-mounted pipes for a sporty look to classic low-slung designs.

• Pros: Significant increase in performance, especially at mid to high RPMs. Often lighter than stock exhausts, improving the bike’s power-to-weight ratio. Produces a more aggressive and satisfying two-stroke sound.
• Cons: May require carburetor re-jetting or other tuning adjustments to run correctly. Can be louder than stock, which might not be desirable for all riders or compliant with local noise regulations.

Custom and Hand-Made Exhausts

For the ultimate in performance and personalization, many riders turn to custom-made exhaust systems. These are often built by specialized tuners who can design an escapamento RD tailored to your specific engine modifications, riding style, and desired power characteristics.

• Pros: Tailored specifically for your bike’s setup, offering the best possible performance gains. Unique designs that can make your motorcycle stand out.
• Cons: Typically the most expensive option. Requires expert knowledge for both design and installation.

How an Upgraded Exhaust Impacts Performance

Installing a performance escapamento RD does more than just make your bike louder. It fundamentally changes how the engine breathes and delivers power.

Enhanced Power and Torque

The primary reason to upgrade is for more power. A performance exhaust allows the engine to expel exhaust gases more efficiently while using the expansion chamber’s pressure waves to pack more fuel and air into the cylinder. This results in a more powerful combustion stroke, increasing both horsepower and torque. The gains are often most noticeable in the mid-to-high RPM range, where two-stroke engines produce their peak power.

Shifting the Power Band

Different exhaust designs can move the power band up or down the RPM range. A pipe designed for racing will typically optimize power at very high RPMs, sacrificing some low-end torque. Conversely, an exhaust designed for street riding might focus on boosting mid-range power for better acceleration in everyday traffic. Choosing the right escapamento RD means matching its characteristics to your riding needs.

Weight Reduction

Aftermarket performance exhausts are often made from lighter materials like stainless steel or even titanium, compared to the heavier mild steel of stock systems. Reducing the overall weight of your motorcycle improves handling, acceleration, and braking, contributing to a more nimble and responsive ride.

What to Consider Before Buying

Ready to choose your new escapamento RD? Keep these factors in mind to ensure you get the right fit for your bike and your goals.

• Bike Model: Ensure the exhaust is designed for your specific model, whether it’s an RD 135, RD 350, or another variant. The mounting points and engine characteristics are different.
• Riding Style: Are you a casual street rider, a weekend canyon carver, or a track day enthusiast? Choose an exhaust that delivers power where you’ll use it most.
• Need for Tuning: Almost all performance exhaust upgrades will require you to re-jet the carburetor. An aftermarket pipe changes the engine’s airflow, and the fuel mixture must be adjusted to match. Skipping this step can lead to poor performance and even engine damage.
• Material and Build Quality: Look for exhausts made from durable materials like stainless steel, which resists rust and corrosion. Check for quality welds and a solid construction to ensure longevity.
• Noise Levels: Be mindful of local noise ordinances. Some performance exhausts are extremely loud and may be intended for “track use only.”

The Final Roar

Choosing the right escapamento RD is one of the most exciting and impactful upgrades you can make to your Yamaha motorcycle. It’s a modification that you can see, hear, and feel every time you ride. By understanding how the exhaust system works and what to look for in an upgrade, you can find the perfect pipe to match your performance goals and give your classic two-stroke the sound and power it deserves.

Frequently Asked Questions (FAQs)

Will a new escapamento RD increase my bike’s top speed?

Yes, a performance exhaust can increase your top speed. By boosting horsepower, particularly at high RPMs, the engine can pull the bike to a higher speed before reaching its redline.

Do I need to change my carburetor jets after installing a new exhaust?

Yes, it is highly recommended. A performance exhaust flows more air, which leans out the air-fuel mixture. You will need to install larger main jets and possibly adjust the needle position in your carburetor to provide more fuel and prevent the engine from running dangerously lean.

What is the difference between a high-mount and low-mount exhaust?

The main difference is aesthetics and ground clearance. High-mount exhausts offer a modern, aggressive look and provide more clearance for cornering. Low-mount systems maintain a more classic appearance. Performance differences between the two styles are generally minimal if they share the same expansion chamber design.

Can I install an escapamento RD myself?

If you have basic mechanical skills and the right tools, installing an exhaust is a manageable job. However, the subsequent carburetor tuning can be more complex and may require a professional mechanic if you are not experienced with it.