Help, Can't Get This Cover Off (i'm The Idiot)

Discussion in 'Technical Help' started by Download7, Feb 24, 2024.

  1. Download7

    Download7 New Member

    Feb 18, 2024
    5
    3
    Vancouver Canada
    #1 Download7, Feb 24, 2024
    Last edited: Feb 24, 2024
    How do I get this cover off? I've taken all the screws around the outside edge out and the 2 "peddles" but it seems like there is something under the "points" section holding it on. I've got a shop manual coming in the mail but it's going to take a while to get here.

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  2. Patrick G Whitehead

    Subscriber

    Oct 1, 2023
    25
    18
    Bishop GA
    Good morning, I assume that you removed the shift lever and kick start lever? Remove the center bolt from the points area and the two bolts on either side. Use a rubber hammer to gently tap around the case. There should be a gasket, and due to the age is probably just stuck firm to the cover. Try setting it up on edge and gently tap down and out a bit. Be patient and keep at it. Maybe try a little heat from a heat gun too. Good luck.
     
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  3. Download7

    Download7 New Member

    Feb 18, 2024
    5
    3
    Vancouver Canada
    Thank you so much for your help!!! How would one remove the center nut? It turns the engine over when I put a wrench in it. How do I brace it without wrecking something?
     
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  4. Samsgrandad

    Samsgrandad Senior Member

    Dec 15, 2019
    514
    243
    Somerset
    As you have worked out you have to stop the engine from turning to undo that nut. How you do it depends on how far you are going to strip the engine down.
    I completely dismantled a Cub engine some years ago and when I got to this nut I had already removed the head and barrel. I locked the engine by placing 2 wooden battens underneath the piston skirt so that it would lock against them when I turned the nut. Once the engine was locked the nut comes undone without too much drama.

    Wood, being softer than the piston is unlikely to cause damage to the piston skirt.

    Best of luck!
     
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  5. Patrick G Whitehead

    Subscriber

    Oct 1, 2023
    25
    18
    Bishop GA
    Bracing the motor from turning is the way to do it. You will most likely need an impact wrench to do this with. The impact wrench alone will probably do the trick.
     
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  6. Download7

    Download7 New Member

    Feb 18, 2024
    5
    3
    Vancouver Canada

    Sweet thank you I'll try that!
     
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  7. Download7

    Download7 New Member

    Feb 18, 2024
    5
    3
    Vancouver Canada

    Thank you so much!
     
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  8. Download7

    Download7 New Member

    Feb 18, 2024
    5
    3
    Vancouver Canada

    That worked great thank you again for your help. Unfortunately right under those pieces there is another thing with moving parts still holding the cover plate on that I can't figure out how to remove and I'm hoping again you our someone has some knowledge to share?

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  9. sprintdave

    sprintdave Nurse,he's out of bed again

    May 25, 2014
    1,507
    750
    Birmingham
    Don't know if it is the same as my old BSA B25 was but it looks like an advance/retard unit for the points. Is there a large thread inside you can put a bolt into by a few threads, if so, waggle the bolt round, the adv/ retard is probably held on a taper. By the sound if things you definitely need a manual or you may end up doing more damage. Good luck.
     
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  10. Download7

    Download7 New Member

    Feb 18, 2024
    5
    3
    Vancouver Canada
    Yea that manual can't come fast enough
     
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  11. MarksMcParts

    MarksMcParts New Member

    Oct 27, 2019
    22
    3
    Anglesey, UK
    I'm stuck on the same job. I've seen in the manual about the need to make a puller using two bolts, but I can't fit a thread gauge into the internal threads to measure them. Can anyone please tell me what size bolts I need to get the cam & backing plate off the shaft? Thanks, Mark
     
  12. sprintdave

    sprintdave Nurse,he's out of bed again

    May 25, 2014
    1,507
    750
    Birmingham
    It was over 40 years ago but I just found a bolt from my trusty(and crusty) tin and grabbed the first thread, no need to go all the way in, and twisted, wiggled and pulled the advance / retard off it's taper.
     
  13. Samsgrandad

    Samsgrandad Senior Member

    Dec 15, 2019
    514
    243
    Somerset
    Can't you check the threads from the bolts you took out of the respective holes?

    I no longer have a Cub manual but the threads will either be BSC (British Standard Cycle) which is 26tpi for all thread sizes or BSF (British Standard Fine)
     
  14. MarksMcParts

    MarksMcParts New Member

    Oct 27, 2019
    22
    3
    Anglesey, UK
    Thanks guys, appreciate the replies. I have a bolt that is right for the inner thread - as you suggested there was a bolt there originally. The one I'm struggling with is the larger diameter one visible inside the cam (post 8 above). There was no bolt in there so I have nothing to measure.
     
  15. sprintdave

    sprintdave Nurse,he's out of bed again

    May 25, 2014
    1,507
    750
    Birmingham
    That is the one I used a bolt I had and wangled it to remove the cam, didn't need to go all the way in.
     
  16. MarksMcParts

    MarksMcParts New Member

    Oct 27, 2019
    22
    3
    Anglesey, UK
    My wangling is no match for yours.... An M8 bolt would just catch in the threads but I couldn't wangle it off.
    I'm no expert on imperial threads - so the question is now, what would be the most likely imperial thread size if an M8 goes in about half a turn?
     
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