Thanks a'Muchly Grumpy for another excellent reply!
I will check that valve sometime over the next week or so. In the meantime I'll start sniffing out what's available out there in the way of Compression Testers, in anticipation of the valve appearing to be in proper order when inspected. I'm fairly certain from memory that the Valve Chest was quite clean when I had the Breather off 5hrs ago. Anyway, we shall see. I'll post again when I know a bit more.
T'will be a fairly underwhelming feeling if it turns out to be Blow-By, considering that the Mower was not much under $600 to buy. C'est la vie, I suppose...
Well, I hope Santa brings you something very nice as a reward for being so generous with your time throughout the year to me and quite obviously a plethora of needy others!
So Best Wishes Again!
Moby Mick
