15 Comments to “BSA B25 Starfire Engine Final Assembly”

  1. I 'cut my teeth' learning bike mechanics on one of these little buggers….. the camplate leafspring broke – twice, and then a geartbox layshaft bearing failed and the result was new crankcases required due to the housing getting mangled….. one set of Triumph TR25w cases for £15 if I remember correctly.Thank-you Hamrax !
    I used to fit two head gaskets to lower the compression ratio as it was always blowing – I made sure the gasket surfaces were flat etc but it still did it, so I would carry the spanners to tighten down the head and do the tappets with me at all times……

  2. Tyler Lewis says:

    The hours you must have put into this.. impressive..! Brought back not so fond memories of rebuilding my A65 ;)

  3. Bravo for the illustrated inclusion.Everyone else should take the hint.

  4. Conner Potts says:

    Love this video.  How can i contact you about doing one?

  5. jameshisself says:

    Nice, but did I miss something or did you just breeze past the cam installation? I saw the followers go in and the gear on the end of the camshaft but no cam.

  6. Problem with this engine was they had a weak crank alloy con rod, and shell bearings,
    if you are going to all this trouble to rebuild the engine it needs a crank upgrade then it
    would be worth it. They were always breaking con rods or the knocking out the con rod
    bearings, the gearbox was good and valve assembly simple but they still had the crank
    and con rod fault, they would  come through the crankcases very expensive repair in

  7. Thanks! I have a 441 which is almost the same. This looked like SolidWorks that I use, Great Job.

  8. Pete Selfe says:

    Dear Crankbuster,
    As an Inventor user I am in ore of the amount of work you must have put into the B25 model.
    How did you measure/model the shape of the cases? Did you scan them?
    I would love to ask more questions about this.

  9. could you also share bsa b12 details 🙂

  10. BikerTuber says:

    Absolutely fantastic! Congratulations on a great piece of work.
    Could someone actually rebuild an engine using this as their only guide? It looks to me as though they could.

  11. Absolutely brilliant. I now have an understanding of how it all works. Thank you.

  12. crankbuster says:

    You can see the book of the film on Lulu.com 18832492

  13. crankbuster says:

    Yes, it looks like it, but the gearbox is built onto the inner timing cover, see my other gearbox video.
    It is there, just hiding from view!

  14. Amazing work Well done. But you forgot the gearbox.

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