Yamaha RD350 Carburetor Basics

The Yamaha RD350 is a classic two-stroke motorcycle known for its strong acceleration and distinctive engine character. Proper carburetor setup is important for good throttle response, starting, and engine performance.

Table of Contents

1. Carburetor Basics

2. Main Jet

3. Carburetor Tuning

4. FAQ

Carburetor Basics

The carburetor mixes fuel with air before the mixture enters the engine. On an RD350, incorrect jetting can cause poor running, hesitation, excessive smoke, or overheating.

Main Jet

The main jet has a major effect on fueling when the throttle is opened significantly. A larger jet generally supplies more fuel, while a smaller jet supplies less fuel.

Jet selection should always consider the engine condition, exhaust system, air filter, fuel, altitude, and temperature.

Carburetor Tuning

Carburetor tuning should be carried out carefully. Make one change at a time and observe how the engine responds. Spark-plug condition, throttle response, and engine behavior can help identify whether the mixture needs adjustment.

FAQ

What carburetor does the Yamaha RD350 use?

The RD350 was produced with different carburetor specifications depending on the model and market.

Does a larger main jet increase fuel consumption?

Generally, increasing the main jet can increase fuel delivery at the throttle ranges where the main jet is active.

Should I tune both carburetors?

Yes. On a twin-cylinder RD350, both carburetors should be correctly synchronized and tuned for consistent engine operation.