| Also known as | 40-387 |
| Diagram | Fig. 7 — GEARCHANGE MECHANISM · ref 4 |
| Subsystem | engine bottom |
| Listed in parts books | 1969 |
BSA Spring, oil pressure release valve
Spring for the oil pressure release valve in the crankcase, as listed in 1969 parts book entries.
This is the spring for the oil pressure release valve, listed in the crankcase section of the parts book. It's a small but important piece of the lubrication system: the release valve it works with is there to bleed off excess oil pressure so the system doesn't build up beyond what the pump and bearings can handle, and the spring is what sets the valve's resistance before it opens.
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The catalog also shows this part number appearing in the gearchange mechanism figure, which is a little unusual for an oil-system spring, so if you're sourcing this for a rebuild it's worth double-checking against your own parts book to make sure you're pulling the right spring for the right job.
We show this one under 40-0387, also written as 40-387 in some listings. The catalog record doesn't tie it to a specific model beyond the 1969 appearances on file, so give us a call and we'll help confirm fitment before you order.
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