First post head question

Just picked up a nice 850 Commando which has an oil leak from the head gasket area on the #1 cylinder. I noticed the head surface was a bit poc marked, wanted youe opinions if I should have my machinist mill it out or not. Thank you for your feedback,
Jon

If its not flat then get it milled but Norton heads do not bend, a few marks will not affect a seal on a properly annealed copped head gasket.

I’ve successfully tidied up worse looking heads by figure 8 sanding them on a glass plate with wet/dry glued on with spray adhesive. This gets you a flat surface and will remove the shallow scratches and pockmarks. I most recently did this to correct a head gasket leak on my BSA A65 and was surprised to see how far from flat it actually was. I started with 320 grit paper and finished with 400. It now seals nicely.

Here are my thoughts if it were my engine.
I don't want to pull the head off again and the sealing surface looks like it could do with a light skim. In addition, the bolts that screw upward from cylinders into the head, do cause (over time) a high spot on the head where the start of the threads has actually deformed a bit up from the head surface.

So I would have it lightly skimmed and know that one possible cause of leak has been eliminated. Why not post photos of your cylinder top surface?

I recently rebuild my 850 motor and after much consulting with Forum, I put a very little sealant on both sides of head gasket where the oil drain hole is and a little around the pushrod passage.

Dennis

Here are some more pics of the head. Surface to me at least looks like it needs skimming to get rid of most the imperfections, thank you for your feedback,
Jon

Do the @Elfix trick first, if after that you still don't like the surface you have lost nothing other than time as material removal is negliable compared to a skim.