I am removing the small brass plug that covers the fuel mix screw on a carburetor so that I can adjust the screw. Is there any reason that I need to replace the plug when I'm done or can I leave it open? If I need to replace it can you tell me what the purpose of that plug is?
The plug is designed to prevent tampering although you should examine the plug to be sure it is not also intended to prevent the mixture screw from moving once the adjustment is made. If the plug is only "concealing" the adjustment screw, the sole purpose is to discourage adjustment once the mixture has been set. Sometimes exhaust gas analyzers are used to fine tune the carburetor and once everything is set obviously you want to reduce the possibility of tampering, hence the plug. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.
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