Zama C1Q-S57C Carburetor

If you have already cleaned the carburetor and replaced the fuel lines but the saw still struggles to idle, stalls under load, or fails to start, the internal components are likely worn beyond repair. Modern ethanol-blended fuels can degrade internal seals and passages that are impossible to clean manually, making a full unit replacement the most reliable fix.

This unit is a direct replacement for Stihl models 017, 018, MS170, MS170C, MS180, and MS180C. It is designed to replace the Zama C1Q-S43C (part number 1130 120 0601).

This is a complete carburetor unit. While it is ready for installation, we always recommend inspecting your existing mounting gaskets to ensure they are still pliable and creating a proper seal; if they are brittle or cracked, you should replace them separately.

You can use a repair kit, such as the RB-77, if you are comfortable with precise mechanical work and the carburetor body itself is not damaged. However, replacing the entire unit is often more efficient because it eliminates the risk of hidden internal damage or debris that a simple kit might miss.

Most replacement carburetors come pre-set from the factory to run within standard operating parameters. However, you may need to perform minor fine-tuning of the idle or high-speed mixture screws once the engine is warmed up to match your specific altitude and local climate conditions.