| Also known as | 40-381 |
| Diagram | Fig. 5 — GEAR CLUSTER · ref 21 |
| Listed in parts books | 1969 |
BSA Spring, non-return valve
Spring for a non-return valve, listed in the gear cluster section of the parts book.
This is the spring for a non-return valve, showing up in our records under the gearbox cluster listing. It's a small internal part tied to the oil circuit that runs through the gearbox area, and the spring's job is to keep that valve seated so oil doesn't flow back the wrong way through the system.
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The catalog entry we have on this one is brief, with a single year on record and no broader model tie-in spelled out. If you're chasing this down for a rebuild, it's worth confirming against your own parts book before ordering, since we can't say definitively which machines it turns up on beyond what's in our listing.
It also appears under the alternate number 40-381, which is the same part just written without the leading zero.
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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