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1972 Combat CNW breather

Discussion in 'Norton Commando Motorcycles (Classic)' started by pierodn, May 13, 2018.

  1. pierodn


    Nov 10, 2012
    A friend of mine has bought the CNW breather, those to be installed even if the engine and gearbox is all together (without modification to the cranckcases).
    The problem is to remove the two studs of the original breather because they unscrewed touched against the gearbox shell and you cannot remove.
    I think thath the only way to remove this studs is to cut off they.
    Let me understand what you have made for.
    Last edited: May 13, 2018
  2. gtiller

    gtiller VIP MEMBER

    Nov 5, 2012
    I think you’re right Piero - it’s pretty tight in there!

    If you don’t want to take off your primary chain so you can move the gearbox, I think cutting the bolts would be your only option.
  3. Burgs

    Burgs VIP MEMBER

    Dec 14, 2013
    It's pretty tight in there, but unless the gear box is all the way forward there should be room to remove the two bolts, unless someone has fitted longer bolts?
    I have a newish primary chain 1500 miles and the gearbox is forward a fair bit but have been able to remove the bolts easily.

    gtiller has said cutting off is an option but how, I suppose there are options but none of them seem to be good to me!

  4. gtiller

    gtiller VIP MEMBER

    Nov 5, 2012
    @Burgs How?

    • Unscrew the bolt as far as possible (until the head is against the gearbox)

    • Saw off as much of the bolt as you can get to with a hacksaw blade (even from underneath I think you would struggle to get close to it with a dremel)

    • Finally unwind the rest of the bolt - you’ll now have space to withdraw it.

    The total length of the original bolts are around two inches (about an inch and three quarters under the head)
    motorson likes this.
  5. batrider


    Aug 9, 2008
    I installed one of these a few years ago on my Combat. The bike was all together. I didn't have any problems like this. There wasn't any sawing involved.
  6. johntickle


    Dec 3, 2009
    Remove the top and bottom gearbox stud and turn the gearbox clockwise (from timing side)
  7. Brithit


    Feb 22, 2005
    I got one bolt out, and cut the head off of the other. I had just set the tension on my belt, and for me it was easier to cut the head off than move the gearbox. I have a little ratchet that fits hex bits, and used that to tighten the bolts. It was fiddly, but doing it in place wasn't that bad.

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