| Diagram | Fig. 29 — CARBURETTERS (Plate 22) · ref 26 |
| Subsystem | fuel |
| Listed in parts books | 1969–1972 |
"O" ring — carburetter flange
O ring seal for the carburetter flange joint on Amal-equipped machines, part 19-3090 (also listed as 622/101).
This is the O ring that seals the carburetter flange where the carb body meets the intake stub or manifold. It shows up in the carburetter figures across several catalog years, which tells you it's a common wear item on the Amal-equipped bikes it was fitted to rather than a one-off part.
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It's a small, simple piece but it does a real job: keeping the joint airtight so the engine draws through the venturi and jets the way it's supposed to rather than pulling unmetered air past a tired seal. A hardened or flattened O ring here is a classic cause of a lean-running, hard-to-tune carb that nobody can figure out.
Catalog records list this under 19-3090 with the alternate number 622/101 also appearing for the same part. Cheap enough and easy enough to miss that it's worth having a spare in the toolbox when you're doing any carb work.
We've never carried this one. Tell us what you're after and we'll go looking — you'll get a price and photos before you commit to anything.
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