Accelerator Pump Diaphragm Assembly, Late Model Weber IDF

This Weber IDF accelerator pump diaphragm has a solid (not sprung) center button. Earlier IDF carburetors used a 2-piece center button to prevent overtravel (early carburetors had a solid linkage that did not prevent overtravel). Sold individually, one per carburetor.

The earlier type has a sprung inner portion in the center button; this later "XE" style has a one-piece metal center button.