Re-torquing cylinder head

I have never thought of slackening off before. I cannot see any logic to doing it that way.

I would suggest you simply go through the tightening sequence in the manual, this has worked for me for many years and heads.

It's my understanding that the 'professional' approach is to loosen off each nut a quarter turn then re-torque to specified figure, dealing with one nut at a time.

Previously wrote:

Hello all - my recently rebuilt Commando 920 has done 700 miles and is due for the head to be 're-torqued' - any advice ? e.g. slacken-off each nut individually or all nuts together and then re-tighten etc. The engine runs a treat but there is beginning to be traces of slight oil 'mist' on the fins above the gasket joint.

Thanks

hello when I torque my cylinder head down I start in the middel and work out ?

Slackening each nut a little won't harm and it is a practice used by many car engine builders. However it is probably not necessary. Since it's an 850 head I assume, was it ok before the rebuild as many are known to leak in that area, third fin up due to porosity etc. The 920 uses a copper gasket I believe butlike the std composite with flame rings needs sealing help around the pushrodopenings. Did you (or the builder) use anything there?It's always a good idea.