OIF B25 differences

[CLIVEDACKUS]

Hi all

Can anyone explain the differences to me between late model (1972) OIF B25SS and OIF Fleetstar engines please?

[AWJDThumper]

I think you are referring to the difference between the 1972 OIF Fleetstar and the earlier B2SS engines. According to Rupert Ratio, the 1972 Fleetstar engine shared some details from the B50 engine of the time; notably, the inner timing cover and the kickstart mechanism off the B50.

[JulianS]

No B25SS B25T or Triumph 250 models were made after May 1971 although existing stock would have been despatched after this. Year letter on frame "E".

Around 130 B25FS were made November 1971-March 1972. Year letter "G"

The factory issued parts service bulletins for the pre OIF Fleetstars detailing the parts and equipment used but I have not seen one for the OIF models.

[AWJDThumper]

Looking at the respective parts books, the main differences are probably:

1972 Fleetstar: B/W wire from points routed via hole above side cover as per B50 rather than just in front of clutch lever as per earlier unit singles. Kickstart ratchet mechanism as per B50 which is different to earlier B25's.