| Diagram | Fig. 3 — CRANKCASE · ref 96 |
| Subsystem | engine bottom |
| Listed in parts books | 1969–1972 |
BSA Alternator rotor (Lucas 54213901)
Alternator rotor (Lucas 54213901) that spins inside the crankcase stator to generate charging current.
19-8019 is the alternator rotor that lives in the crankcase behind the primary drive, spinning inside the stator windings to generate the bike's AC current. Lucas number 54213901 is stamped into the catalog record as the actual maker's part, so if you're cross-checking against a Lucas parts list or an old electrics catalog, that's the number to match up.
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On engines using this generator setup, the rotor is keyed or fitted to the end of the crankshaft and turns with it, so timing and balance aren't something you fiddle with separately — it's a straightforward swap-in item, but you want to make sure the stator and rotor are matched for the same charging system before you commit to buying one.
Our catalog record covers appearances from 1969 through 1972, but it doesn't call out a specific model by name, so confirm fitment against your own bike or parts book before ordering.
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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