| Diagram | Fig. 27 — PETROL TANK (STEEL), TWIN SEAT · ref 24 |
| Subsystem | fuel |
| Listed in parts books | 1970 |
BSA Filler cap, domed, 4 gallon
Domed filler cap for the 4-gallon steel petrol tank, part number 75-8009.
This is the domed filler cap for the 4-gallon steel petrol tank, part number 75-8009. It sits on top of the tank and covers the fuel filler neck, keeping fuel in and road grime out while you ride.
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The catalog places this cap on the petrol tank figures alongside the twin seat and handlebar/controls listings, so it's tied to a specific tank rather than a universal fit. Our records show it appearing across 1970 catalog listings for the 4-gallon steel tank setup.
If you're replacing a lost or damaged cap, check that your tank takes this domed style before ordering — filler neck diameters and cap styles varied across tanks, and the catalog entry here doesn't spell out compatibility beyond the 4-gallon tank it's listed against.
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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