Britbike forum Forums British Motorcycle specific Brands Triumph bulletin board 67 T120R carb / air cleaner question

The 67 Bonneville I just inherited is missing air cleaners. Parts book says the carbs are AMAL Mono 389's. Under closer inspection, the carbs appear to be different; one side has threads for attaching adapter/the air cleaner, the other side does not. The bike is being shipped at the moment so I cant take a pic, but from memory, the non-threaded side looked to have some kind of pattern where the threading would be. Hope that makes sense.

Has anyone seen that before? I assume this isn't correct, different year carbs ? Different part numbers?

Thanks in advance for any info.

Forgive the noob!

The factory installed mono bloc carbs on your 67 bike are 389/95. The air intake side of the carb is threaded and an adapter is threaded onto it. the air cleaner slips over the adapter and is tightened with a hose clamp.

The pattern where threading would be could just be wear from a loose filter or loose adaptor flogging the threads out. The filter working and vibrating might have worn the tops of the threads away. The carb metal is very soft.

I wouldn’t worry until I saw the bike and checked the carbs. .

I have a Triumph with an adaptor ring glued in with silicone for exactly the same reason. That bike runs like a champ.

No I didn’t do the gluing......it came that way.
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Lucky for you there were many '67 T120 Bonnevilles sold, and thus many 389/95 carbs show up on EBAY and in the swap meets, so finding a good one shouldn't be difficult.

Thanks for the replies! The bike should be here tomorrow, so I'll be able to get a better look at it. Ginge may be right about the wear.

Turns out there is/was an adapter of sorts covering the threads on one of the carbs. Not the adapter the air cleaner slips on to, it just covers the threads and adds no length.