The FAJS 40 IDF is a complete downdraft carburetor and a well-known replica of the classic Weber IDF carburetor. It comes with standard jetting and extra linkage levers for both left and right-hand mounting, making it perfect for dual carburetor setups on boxer engines (e.g., VW Type 1) or V-engines.

The carburetor can be tailored to your needs. When ordering, you choose as an accessory whether you want the carburetor delivered with velocity stacks (trumpets) and/or a choke housing, or if it should be delivered entirely without these accessories.

Standard Jetting (Out of the box):

• Choke tube (Venturi): 28 mm
• Auxiliary venturi: 4.5
• Main jet: 130
• Air corrector jet: 170
• Emulsion tube: F11
• Idle jet: 52
• Pump jet: 50
• Needle valve: 200
• Float level: 12 mm

Important information: As this is a Weber replica, some tuning may be required to achieve optimal running conditions, and it may not always perform flawlessly out of the box like an original. Some of these carburetors may flood, which is often due to the needle valve. Misab strongly recommends purchasing and replacing the needle valve with a genuine Weber needle valve for improved reliability. During installation, it is crucial that the fuel pressure does not exceed 0.25 Bar (approx. 3.6 PSI). Also, ensure that the jetting is adapted for your specific engine and that the system is completely free from vacuum leaks.