It sounds as if the only issue is that there is a mismatch between your expectations, and your engine's design and manufacturing standards.
You can say that again Grumpy!... The thing may not have been quite as expensive as a Honda, but it was certainly a lot dearer than a Sanli or a Gardenline, and I didn't see any oil leaks on my neighbour's example of the latter-brand when I changed her oil a while back (and the factory-supplied oil that came out of it was as thin and black as Coca Cola...)
Just to put the blow by to bed for good I'd pull the air filter and if it's dust dry there is no blow by or very little...
Good thinking Chris - I did that just now, and it's clean and dry in there.
Oh yeah how does the engine actually run?
She runs very well. Doesn't hunt around for revs at all, and doesn't bog down too much when you hit the thick stuff - just changes exhaust note a little. Always starts first pull if you prime it, 2nd or 3rd pull (depending on how long since the last mow) if you don't prime. Idles very happily too, and going by sound and feel when you shut her off, she feels like there's plenty of compression up her sleeve.
Out of curiosity what makes you pull the plug to see the burn has it not run right from new?
I started keeping an eye on the Plug once I realised that the Carb could not be adjusted in any way (because the needles are all preset, unfortunately...), and I also wanted to see whether the Plug changed colour after the "run-in" period and the first "5hr" oil-change. Not too long after that - when I noticed that the Plug colour wasn't changing to "tan", I pulled apart the Air Filter and noticed that the factory hadn't quite packed it properly; one edge of the pleated paper cartridge was snagged on the edge of the gauze from the pre-filter, and this had allowed a "free run" onto the paper cartridge for a large amount of dirt and debris. I thought then that I had found the plug-colour problem, but kept checking the Plug all the same to see whether it came good (which it didn't...). I've toyed with the idea from time to time of running a slightly warmer Plug in the thing, but have never got around to seriously trying to do something about it.
I note your O-Ring comments, and they are fair. I suppose when I think of O-Rings actually doing some work, I think of the spindle O-Ring on a hot-water tap, which has real movement and (admittedly lower) temperature to contend with, in addition to a constant supply of muck coming down the spindle from below the tap-handle.
To my mind, the O-Ring on my motor's Oil Tube mustn't be quite thick enough, because there doesn't seem to be much resistance and effort required to pull the Tube in and out of the parent-orifice for it in the crankcase. I actually contacted Briggs a couple of months ago to ask whether they knew if the "spare part" version of the O-Ring was merely just the same thickness as the factory-installed item, but since I got redirected to Briggs here in Australia, they unsurprisingly ended up being a little in-the-dark regarding the specifications of both O-Rings - original and spare. Someone in my predicament wouldn't know if there had been a change somewhere along the way in the specification due to warranty claims and feedback, and in point of fact - the same might have happened to the Oil Tube itself, which could have grown in diameter by a smidgen since I bought my mower. Heck, I haven't even mentioned the Seal under the Oil Cap yet...
Well, I better get myself organised, because there's certainly some mowing to be done with the weather we've been having lately here in Brisbane!
Best Wishes for the New Year to both of you if I don't talk to you again before tomorrow!
Mick.
