thanks grumpy, i do suspect a bit of both (valves and rings) as this is an old mower that was previously a contractors (hr214).
I have done the oil in sparkplug hole trick and have noticed an increase in compression so i guess it does need new rings.
(i have also dismantled the mower and just moving the head of the piston around i feel 1-2mm or so of freeplay in the bore which i guess is no good, i know its not supposed to be a perfect fit but when i can move the piston around and see oil coming out of the bottom between the piston and the bore, it cant be a good thing).
also, the bore seems in perfect condition, do i really need to hone it before reinstalling new rings (it would involve buying a honing tool for me and i cant see myself honing to many bores to make it worth it).
