Yep it was the rings that were broken and the piston, barrel, circlip and gugdeon pin. F@#K!!!!
As predicted the mechanic had a listen to the pipes while I wound over the engine, "its not you valves, it's the rings for sure", then he squirted a little oil into the top of the piston, attached the compression tester and I wound it over and we got 100psi on the gauge for a few strokes... "yep rings"
So he left and I quickly set about removing the head and barrel to see what I would find..... well here it is below!!
The circlip has come off and caused a shit load of damage!!
Now my question is will the Nikasil barrels and pistons from a 1982 R100rs fit onto my 6th month 1978 R100rs
I can get a good pair quickly and locally from a friend..
PS - Sibbo, when you replace your push rod tube seals, check and recheck the gugdeon pin circlips when you reattach, I did a few times as I was a little paranoid about this but something happened, but I made special attention all the same.
