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Drilling out 961 OEM muffler baffles

Discussion in 'Norton Motorcycles (Modern)' started by gchoppin, Dec 30, 2017.

  1. gchoppin

    gchoppin

    Joined:
    Sep 26, 2017
    Bounced this idea around with Richard 7. I love the look of the OEM 961 mufflers. Thinking about the possibility of drilling out the baffle with a metal hole saw. I've done this with many OEM Harley exhaust and ended up with great sounding pipes. Got the idea by looking at how the exhaust tip is configured. A lot like older Harley tips. Anyone had any success in the endeavor or am I going to be the pioneer here?
     
  2. pingu-nz

    pingu-nz

    Joined:
    Jun 24, 2011
    I got mine drilled out ,
    Big hole saw took out the 2 back baffles in the cans and removed cats .
    And yes improves sound considerably but looks stock standard .
    Cheers
    Paul
     
    richard-7 and gchoppin like this.
  3. gchoppin

    gchoppin

    Joined:
    Sep 26, 2017
    Great news. Thought I read I thread where you drilled yours. Got a decat pipe ordered. Did you get the ECU reflashed?
     
  4. pingu-nz

    pingu-nz

    Joined:
    Jun 24, 2011
    See how it runs once you have done it ,
    From memory i got the ecu reflashed ,but since then have gone to a power commander for fueling .
    cheers
    Paul
    [​IMG]
     
  5. DODGY DEN

    DODGY DEN

    Joined:
    Jul 7, 2016
    Hello,
    Interested in a bit more information on removing baffles, would a vertical rotary metal cutter be enough to remove the baffle I have measured the diameter at 34mm at the rear of the exhaust can, would this be enough ?
    Dodgy Den.
     
  6. gchoppin

    gchoppin

    Joined:
    Sep 26, 2017
    metal hole saw is the way to go. Measure carefully and don't go too big on the first cut unless your very sure whats on the other side of the metal you're cutting. Too large and you may cause a problem with structure of the can. Good luck. I'm on the same path. Pingu NZ's pipe tip looks a little larger than mine. We'll see.
     
    pingu-nz likes this.
  7. Ferreteer

    Ferreteer

    Joined:
    Sep 20, 2019
    Does anyone have photographs or at the least a schematic of what lies inside a standard Norton silencer so I know what I'm getting myself into with this hole saw malarkey?
     
  8. Stephen_Spencer

    Stephen_Spencer

    Joined:
    May 31, 2017
    Had my standard longs ‘modified’ by a bike exhaust specialist in Brisbane. Original look and awesome sound for a fraction of the cost of a replacement. I did not see the process however, they removed the cat sections and replaced them with straight pipe and also had to remove the end caps to gut the silencers. The end caps were then welded back on. They did a great job, ECU was changed and she has run sweet as a nut ever since. Starts and settles on 1200 revs immediately and stays there. Ran like a dog before this process. As a cautionary comment it took these guys several attempts, I assume removing more of the internals each time to get a nice rich tone from the exhausts. This took quite a long time. Despite this you may find it almost as cheap going to a specialist as it would doing it yourself and paying Norton for the decat pipe section.
     
  9. Deano

    Deano

    Joined:
    Jul 24, 2019
    Interesting idea, plus the stock silencers are stainless steel vs chrome plated on the factory louder pipes that I’ve seen, so that’s a bonus in the UK at least...
     
  10. Ferreteer

    Ferreteer

    Joined:
    Sep 20, 2019
    Mine is an early Norton and I have been told it has no cats from the factory. I bought it privately a few weeks ago with the optional straight through pipes fitted but I have just noticed that the left pipe has completely rotted away underneath and will be dangerous around the hanger bracket quite soon Hence my need to replace. I have watched the various videos of people hole sawing baffles out on other makes of bike. The YouTube videos always seem to be quite simple when when the end and is cut the baffle simply pulls away. A couple of members here seem to have done it already. I am hoping someone who has the experience can contribute. My plan is to makeup a long hole saw by butt welding one of the cutting inserts to the same diameter steel tube about 2 feet long then at the other end weld in a mandrel and Bush. With this it should be possible to easily drill through the silencer end cap and straight through any central baffle. is there anyone with the experience to accurately describe or have a photograph of the internal structure
     
  11. Ferreteer

    Ferreteer

    Joined:
    Sep 20, 2019
    Anyone??
     
  12. TonyA

    TonyA VIP MEMBER

    Joined:
    Jan 16, 2015
    I have never done it . Maybe Max at Norton will give you advice ?
     
  13. pingu-nz

    pingu-nz

    Joined:
    Jun 24, 2011
    Ferreteer

    I had my OEM baffles drilled out by a experienced motorbike exhaust builder.
    He also drilled out the OEM cats, so my exhaust system still looks stock factory.

    cheers
    Paul
     
  14. Ferreteer

    Ferreteer

    Joined:
    Sep 20, 2019
    Hi guys and thanks for everybody's feedback. Unfortunately I am still no further forward. Is there anybody within the membership who can tell me unequivocally through experience that using an Xmm hole saw will release the long perforated baffle and allow it to be pulled from the silencer as per all of the the Harley-Davidson muffler videos on YouTube. Or is it more complicated than that. Is the the long perforated tube still attached by weld deep in the silencer therefore requiring a very long hollow hole saw? Clearly I'm asking this because I don't know what the internal structure looks like and as per the previous reply by another member I don't want to cut the wrong diameter and weaken the internals.
     
  15. Deano

    Deano

    Joined:
    Jul 24, 2019
    Without taking an expensive gamble, I guess the only way you may find out is to try & get hold of an accident damaged scrap one & cut it open... :(
     
  16. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    Ferreter, I think you’d be taking a huge gamble doing this. Just because some HD silencers can be modded thus doesn’t mean your Norton ones can.

    Clive (on this forum) had the factory make him some one off long silencers, stock on the outside, less on the inside, he might be able to shed light on what they’re like inside.

    Failing that, as they’re stainless and there’s no chrome to spoil, a specialist could cut them open and modify them for you.

    But with such a route, my worry would be the fuel mapping. If you use stock or after market factory parts, you know there is a relevant factory map. If you make you own silencers, how will you know which map to use?
     
    Last edited: Sep 28, 2019
  17. Ferreteer

    Ferreteer

    Joined:
    Sep 20, 2019
    Guys my new Norton ownership is taking a nosedive and I haven't even turned a wheel yet.

    Let me recap, I bought the bike with straight through long pipes in chrome. The left one is rotted half of it's circumference at the internal baffle that is situated approximately halfway along the rear hanger slot.

    I started to look for for an economic solution and found this site and this thread extolling the virtues of drilling out the standard cans.

    On the strength of the first few posts in this thread I went out and locally managed to find a set of standard long cans for sale at a reasonable price.

    These are also in Chrome.

    Then after asking for a little more information I found out that the chap who said he had drilled his cans out in fact hasn't. He had given them to a specialist who had removed the cones, gutted the silencers and re welded the cones. This was not, I assume, what the original poster or indeed myself were intending to do.

    As for this whole locked ECU malarkey I am absolutely flabbergasted that the factory has not already had a restrictive activity ( ie insidious design )class action against it for locking out the ability of owners who wish to customise the airbox the pipes or even the air filter and then easily modify or download a fuelling map as i can with my speed triple for example.

    it makes things even worse when I find that the only dealer within 200 miles of me has just dumped Norton. After Norton has been trading for 10 years this just leaves them with three dealers in the whole of the UK, all in the south. This is not congruent with a design philosophy of having to return parts or indeed the whole bike to the factory and not being able to modify "in the field" as it were.

    I did the distinguished gentleman's ride on Sunday, I went on my buell......
     
  18. Eljahara

    Eljahara VIP MEMBER

    Joined:
    Jul 8, 2018
    Are you saying Teasdale has dropped Norton?
     
  19. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    Yes they have.
     
  20. MxMartin

    MxMartin

    Joined:
    Nov 13, 2017
    Teasdale still show Norton on their web site but all models 'out of stock'

    Did Norton make chrome silencers? I thought they were all stainless.
     

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