| Diagram | Fig. 1 — CYLINDER HEAD, EXHAUST PIPE · ref 17 |
| Subsystem | engine top |
| Listed in parts books | 1969–1972 |
BSA Tufnol washer, carburetter joint
A Tufnol insulating washer fitted at the carburetter joint to help isolate carb heat from the cylinder head.
This is the Tufnol washer used at the carburetter joint, where the carb mounts to the cylinder head or manifold stub. Tufnol is a resin-bonded fibre material, and its job here is to act as an insulating spacer between the hot cylinder head and the carburetor body, cutting down on heat soak that can affect fuel and float bowl temperature.
Read more
It shows up across cylinder head and cylinder barrel/exhaust pipe figures in the catalog, which tells you it lives right at the intake tract junction rather than anywhere in the exhaust itself. Appearances in our records run from 1969 to 1972.
These washers get compressed and can harden or crack over time from heat cycling, so if you're pulling the carb off for cleaning or a rebuild it's worth having a replacement on hand rather than reusing a tired one.
Sorry if we got something wrong here. If you think this information isn't correct, .