Plug

[spike123]

Hi does anyone know what the thread and size tap needed for the sludge trap plug on 1967 bsa a65

[Spaceman]

According to British Bike Bits it is 3/8" BSC X 1 1/2":

https://www.britishbikebits.com/flywheel-bolt-bsa-a50-a65-1964-72

[DAVE BRADY]

Hi,

Attached is screenshot from Feked site.  This has BSF and is for the earlier models so most likely for your crank is a UNC thread as mentioned on other sites.

Dave.

Just had a look on SRM site and they have the thread as BSF from '66 on.  So a bit confusing as usual with some BSA specs.

[Spaceman]

Sorry - looking at the wrong flywheel part

[JulianS]

7/8 inch x 20tpi.

[spike123]

Thanks. Guys