What are the purposes of the main fuel strainers?

• A. Filter air entering the carburetor
• B. Increase fuel pressure
• C. Collect water and sediment, keep foreign matter out of carburetor
• D. Reduce fuel temperature

Answer: (C)

Strainers in the fuel system are there to keep the fuel clean before it reaches the carburetor. Their main job is to collect water and sediment and keep foreign matter out of the carburetor. Water in fuel can cause corrosion, poor combustion, and icing in the carburetor, while dirt and rust can clog jets and passages, throwing off the fuel metering. The strainer traps these contaminants and often has a drain to purge the collected water and sediment. That’s why this option best describes the purpose. Filtering air, increasing fuel pressure, or lowering fuel temperature aren’t functions of the main fuel strainer.