How to Adjust a Carburetor for Fuel Efficiency?

[VanLeila]

If it's a fixed main jet, you can wrap one or two thinner copper wires inside the jet to reduce the fuel flow. First, screw the needle valve all the way in, then rotate it counterclockwise about one and a half turns. Multiple adjustments may be required to achieve an optimal level.

[MacDavid]

In my over ten years of working with cars, adjusting carburetors for fuel efficiency is quite an art. Generally, you need to first remove the carburetor and thoroughly clean the carbon deposits and dirt with a cleaner, as blockages can lead to poor fuel supply and waste. Then, adjust the mixture screw—this is the crucial step. Use a small wrench to slowly turn it, bringing the air-to-fuel ratio close to 14:7 for more efficient combustion. After starting the engine, listen carefully: if the RPM is unstable or there’s a strange smell, the mixture might be too rich and wasting fuel; too lean, and the engine may stall. I often help friends with this, and it can save about 10% on fuel while extending the car’s lifespan. But be careful—don’t attempt it blindly; getting professional assistance is safer. Finally, maintain regular upkeep, like changing the oil on schedule, and pair it with smooth driving habits to boost overall fuel economy.