Thanks to Panic and Cottens persistance of the possible dreaded intake tract leak being the root of my problems and with finally using Cottens excellent leak detection instructions I found the front cylinder inlet nipple to be loose.
The cylinders are new Scout barrels from Flathead power - Sweden with less than a 100 miles on them. I'm not blaming anyone as with all things of this nature someone along the line has trucked up - possibly me ( I'm the third owner of the bike in less than a year !) so what I need to do is sort this out efficiently and at reasonable cost.
My questions are:
1) Are the nipples screwed into the heads or pressed in on these repro barrels.
2) The manifold nut is rotating with the nipple, my best guess is to cut the nut carefully- any other suggestions ?
3) Depending on 1 above, if threaded, will I be able to make a repair without removing the barrel or is re-machining and a new nipple a foregone conclusion.
I look forward to any help, advise and suggestions you may have.