Norton Commando Cylinder Base Tightening Sequence and Torque

Here is a graphic that shows the preferred stud and nut tightening sequence and required torque for the cylinder base on a pre-1972 750 Norton Commando.

Grant Tiller

This is also available as a PDF download in case you want to print it out to keep handy in your workshop!

Grant Tiller

Just click here to download

For the launch of the Combat engine in 1972, the Norton engineers made an effort to move some of the hardware over to UNC and UNF thread forms.

Here is a graphic that shows the preferred stud and nut tightening sequence and required torque for the cylinder base on a post-1972 750 Norton Commando.

Grant Tiller

Here is a PDF that you can download in case you want to print it out to keep a copy handy in your workshop.

Grant Tiller

Just click here to download

The requirements are a little different for the 850 Norton Commando – the crankcase is stronger, and there are four long through bolts (C, D, G & H) which run the height of the cylinder.

These can only be accessed with the head off.

Grant Tiller

Again, available for download as a PDF file for you to print out and keep.

Grant Tiller

Just click here to download

4 replies

  1. hi grant
    Its paul again with the commando timing issue, I managed to use 2 12v coils from an a65, and at long last got the timing light to work, and did indeed time it correctly it was a long way out, quite suprised it ran ok ish before, 15 / 20 degrees, dumb question it should not make any differeace once I return it to dual output coil, correct ! have googled this issue with timing and dual coil but found almost no refs (using different e mail address)
    Thanks grant

    • Hi Paul,

      MK3 Commando running a Boyer electronic ignition if I remember?

      With electronic ignition two coils in series will behave the same as a single dual output coil so timing will be pretty damn close.

      Be careful if you are using two 12 volt coils, even as a test in the short term – effectively in series, this is behaving as a load for 24 volts.

      It will not do your electronic ignition any good, and it will drain your battery pretty fast.
      The Boyers in particular get upset pretty easily!

      Let me know how you get on when you reattach your dual output single coil, and if that flatspot has disappeared!

  2. Hello Grant, I have a MK3 and putting +.020 Pistons. The manual calls out for boring to 3.052 in. Is there a plus or minus tolerance. Thanks

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