Yamaha Two-Stroke Carburetor Performance

Yamaha two-stroke carburetors, typically Mikuni-made units, perform a critical function by mixing the fuel just right for two-stroke engine combustion. However, proper tuning and jetting of the carburetors can make them perform more efficiently.

Adjusting Mid-Range and High-Range Jetting

The major adjustments that can be made on a Yamaha carburetor involve adjusting the jetting for performance engine conditions. Increasing the amount of fuel in the air-fuel mix by increasing the carburetor jet sizes will increase the available energy for the tuned engine.

Fuel Flow and Cleaning

If a Yamaha carburetor has been used for a while, a good maintenance cleaning and spray can increase fuel flow and remove old gunk. The carburetor needs to be removed and taken apart to perform an effective cleaning with a spray solvent. Once assembled, the flow channels should work significantly better.

Flatslide vs Roundslide

Carburetor performance can be upgraded by changing the carburetor model, which is identified by the carburetor gas flow control mechanism (the slide). Roundslide carburetors are common and typically installed as stock equipment. However, flatslide carburetors are available in most sizes and offer faster throttle response. Riders looking for quicker gas response should be looking for a matching flatslide.

References

• "Two Stroke Performance Tuning"; A. Graham Bell; 1999
• ATVRiders.com: The Jetting Guide
• Mikuni American Corporation: Tuning Guide

Resources

• Read this Article in Spanish
• Yamaha: 2006 Yamaha Blaster Specifications