For GEN-3 KEIHIN FCR-MX carburetors 37mm - 44mm with Non-Removable adapter.

For FCR-MX carburetors with removable adapter see the page with adapters

63 mm Outside Diameter
43.5 mm total length
34 mm added length to carburetor

You will need to file the small lip of the back of the carburetor fitting in order to fit this adapter

A good adhesive or epoxy is recommended to prevent movement that will lead to air leak
 

A wide range of Carburetors, Carburetor parts, Vent line kits, Gasket kits, jetting components are in stock.

If you don't see something you need please ask.