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Flaws in reproduction air filter

Discussion in 'Norton P11 Motorcycles' started by Trialbyfire, Feb 4, 2020.

  1. Trialbyfire

    Trialbyfire

    Joined:
    Oct 30, 2014
    My 1967 P11 came to me with a mikuni conversion. I am attempting to replace with amal 930's and a reproduction air filter. My assessment is that where the carbs attach to the air filter the holes are not only uneven but slightly too close together. I will try to add photos. This is never going to work without filing or grinding down the inside flanges and also it appears i would need to shave some off in the areas that sit opposite the throttle adjusting screw. I doubt i can take much off of that area without ruining brand new carbs. Has anyone ever wrestled with the repro air filter?
     
  2. Trialbyfire

    Trialbyfire

    Joined:
    Oct 30, 2014
  3. Trialbyfire

    Trialbyfire

    Joined:
    Oct 30, 2014
  4. p400

    p400 VIP MEMBER

    Joined:
    Jul 14, 2014
    Norton side by side Amals require the supplier or owner to slightly file a little off the mounting flange at the inside to allow fit.
    Simply standard procedure.
    The new Amal 930 castings also seem to "knock" at the excessive casting to the inside as well, so I just grind off all of this casting,
    With reason being to allow access to the inside mount nuts.

    If you purchase "reduced hex" nuts for this Norton Amal 930 pair application, the Amal mounting (on any Norton) becomes much easier.

    NewAmalsOnP11a.jpg
     
    pierodn likes this.
  5. p400

    p400 VIP MEMBER

    Joined:
    Jul 14, 2014
    The tool I use to trim Amals is a standard Dremel with a cutoff wheel.
    This does require some acquired skill that is learned about your third Amal trimming. DremelCutOffAmals2.jpg
     
  6. p400

    p400 VIP MEMBER

    Joined:
    Jul 14, 2014
    photobucket photo posting are not good for this forum.........or any forum in my opinion.
    You might find another photo post method.
     
  7. Trialbyfire

    Trialbyfire

    Joined:
    Oct 30, 2014
    Thanks for the info. All sounds manageable. I'll find a better source for hosting photos and post a pic once its all on the bike
     
  8. andy johnson

    andy johnson VIP MEMBER

    Joined:
    Aug 12, 2017
    on the subject of the inner nuts , i remove the stud and rethread an m8 allen screw (cheaper than buying the imperial allen screw) then machine down the outside diameter of the head so the allen screw wiggles in past the carb casting . this way with a long allen key on a ratchet makes removal and replacement a lot less fiddly than nuts !!
    andy
    oh and yes i had same issue with grinding the carb flanges , a dead easy job.
     
  9. Tornado

    Tornado VIP MEMBER

    Joined:
    Dec 5, 2017
    Note VIP membership here lets you post images directly to the site. No outside hosting required.
     
  10. p400

    p400 VIP MEMBER

    Joined:
    Jul 14, 2014
    OEM Amals from a P11.
    Note removed areas.

    Yes, BSW/BSF allen bolts for the inside Amal mounts on your P11, easily found on ebay uk or from UK vendors, maybe British fasteners website as well. Don't retap the head. Correct fasteners easy find.

    20180819_P11FactoryAmalPair4.jpg
     
    Last edited: Feb 5, 2020
  11. Trialbyfire

    Trialbyfire

    Joined:
    Oct 30, 2014
    Thanks very much. Everything is sitting together nicely now. I cant say my work looks as nice as the photo above, but it'll be tough to see the alteration once its mounted.

    Solve one problem, find another. I could have sworn i had the original carb manifolds in a box of parts that came with the bike but its not the case. Only have the manifold for the mikuni.

    This bike is frame # 121586 i will try to add to the yahoo group
     
    Last edited: Feb 6, 2020
    jerrykap likes this.
  12. mdt-son

    mdt-son

    Joined:
    Jan 19, 2012
    The yahoo group is defunct and has moved to a new site. You need to go to https://ajsmatchless.groups.io/g/main

    -Knut
     

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