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Dunstall 850 overhaul

Discussion in 'Norton Motorcycle Rebuilds' started by 850commando, Sep 11, 2018.

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  1. 850commando

    850commando

    Joined:
    Nov 1, 2014
    hopefully just something that will be fine once it starts to run...
     
  2. o0norton0o

    o0norton0o VIP MEMBER

    Joined:
    Apr 27, 2015
    When my lifter pad delaminated while I was idling in the driveway, it did NOT go anywhere. It sat right in place on top of the cam and made a slap/rapping noise that sounded bad enough to me that I knew I was going in for a look. When I pulled the barrels off, I looked down and saw the entire pad sitting on top of the cam lobe and thought, "where the hell did that come from?" Then I looked at the underside of the barrels and saw the missing pad on one of the lifters, and it all made sense. I imagine if I turned the bike over slowly, it would just go, "click, click, click"...

    If I was you, I would removed the valve cover and use a pushrod up against my head to hold against the intake valve tip while someone rotates the engine. The pushrod will conduct the sound better than air, so you can use it against parts of the engine to see if the "click" is coming from a particular valve, or a particular part of the engine.

    Personally, I'd pull the head and barrels. When I lost the stellite pad on my commando, I had the barrels off in 3 hours. Luckily Jim Comstock took an interest in my dilemma and hooked me up with what I needed. It's just not worth the risk of trashing the cam and whatever else...
     
  3. norton bob

    norton bob

    Joined:
    Nov 29, 2013
    Loose valve guide going up and down.
     
  4. grandpaul

    grandpaul VIP MEMBER

    Joined:
    Jan 15, 2008
    Could be a sticking cam follower, too...
     
  5. marinatlas

    marinatlas

    Joined:
    Nov 4, 2007
  6. marinatlas

    marinatlas

    Joined:
    Nov 4, 2007
  7. marinatlas

    marinatlas

    Joined:
    Nov 4, 2007
  8. o0norton0o

    o0norton0o VIP MEMBER

    Joined:
    Apr 27, 2015

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