Atlas head question

Here are a couple of photos of my head, when I purchased my bike it was leaking a little oil and bubbling at the back of the head, assumed the head needed re-torqueing, took it off for good measure.

Look at the rear bolt holes ( near spark plug, carbon and oil staining ).

There is some sort of insert that has been installed, which is fouling the head gasket, as can be seen by the indent in the head gasket, is this type of insert common in the Atlas head ?.

No, but it might work if machined flush with the surface.

Looks like a home made insert, should be a helicoil type insert really.
Best bet is to carefully file flush with head & use a composite gasket, as it has a bit more give.
Good idea it to lap the head onto the barrel with grinding paste, (but nobody really listens to engineers, so I am probably wasting my breath).

No reason for a helicoil. It's not a threaded hole, just a straight through hole for the head bolt. Is it possible someone fit the insert to convert a Commando head to fit the Atlas? I'm a Commando guy, but I seem to recall that the Atlas had 5/16" head bolts instead of the Commando's 3/8". If that's the case, filing or milling the head to bring the insert flush with the head might help. The copper head gasket looks like a Commando gasket, with the larger holes for the 3/8" head bolts. Do the Atlas barrels still have the spigots?

Ken

Thanks Gents,

Didn't think it would be standard, but its better to ask the question........

The bike is a commando with and Atlas head and Barrels, which I will now definately be correcting, it does look like a previous owner, lets call him "dumb ass", tried to make the Atlas head fit the original commando barrels, he drilled out the holes to 3/8 then realised the holes now extended out into the fins and as a remedy, installed these sleeves. Looks like a completely half assed job, off to the scap heap for the head.

For Sale, Atlas Barrels, in good order, previously owned by dumb ass, perhaps now owned by a completely different dumb ass.....

Thanks again.