| Diagram | Fig. 1 — CYLINDER HEAD, EXHAUST PIPE · ref 24 |
| Subsystem | engine top |
| Listed in parts books | 1969–1970 |
BSA Valve spring (inner)
Inner valve spring (PN 65-2495) for the cylinder head, working with the outer spring to keep the valve seated and closed.
This is the inner valve spring listed in our records as 65-2495, showing up in the cylinder head figure. Inner and outer springs work together on the valve stem to pull the valve closed after the cam lets it open, and to keep it seated against the valve face at speed. When one goes soft or breaks, you get valve float, poor running, or in a bad case, a dropped valve.
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The catalog entries we have for this part run from 1969 to 1970, and it also turns up referenced in the exhaust pipe figure, which is common since cylinder head hardware and exhaust port work get grouped together in the parts books. Beyond that, we don't have more detail on this one.
If you're rebuilding a head and pulling springs, it's worth checking the inner and outer together rather than just replacing one, since they're both doing the same job under the same conditions. Give us a call and we'll confirm fitment before you order.
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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