Plugged Idle Jets can result from dirt, and other debris getting into the carburetor, and pooling up in the top of the carburetor cover. On this cover, there are two small holes that are used to take in extra air, in addition to the air that is sucked in through the velocity stacks. When excess debris gets through these holes, it ends up clogging the idle jets. The Weber Jet Doctor blocks these holes, and provides a 'snorkel' to breathe fresh air from about an inch and half above the top of the carburetor cover, thus eliminating the ability for the debris to seep into carburetor's idle jets. An O-Ring gasket also provides a tight seal, to make certain that no debris can get inside the idle jets, and ruin your day. Check out the EXTENDED INFORMATION tab above to see a technical explanation and installation guide for the Weber Jet Doctor Kit. Hot VWs printed an article back in the December 2004 issue, about the Weber IDF Jet Doctor.