Guys, I appreciate the suggestions. The oil ring is looking more and more likely. I assume their is no way to test for this fault without cracking the case, un-doing the rod bolts and sliding the piston out.
I also wanted to confirm that is ok that I seal up the crankcase with rtv silicon when I crack the case, that's of course of the gasket gets damaged. Being a fairly new mower I hope the crank seals will be ok.
Mark, I have been looking at a few different versions of leak down tools on ebay and through normal retail shops. Can I ask what you bought and the rough pricing?
I'd appreciate anyone else's thoughts on the value of a leak-down tester for general hobby use only.
