New YTH18542 B&S motor smoking

Bought new about a month ago from Lowes and had it delivered and all setup.

Just getting to the 5 hour mark now and have a question before changing the oil/filter.

Whenever I start the mower, I always check the oil level before starting and it always shows full, as it should. But the last two times I've used it, I get a lot of blue smoke out of the exhaust as soon as the mower starts to move. This continues for about 5-6 seconds, then stops. Has the smell of burning oil. Then I noticed the last time I ran it, the oil level was just a smidge low. Engine sounds fine, doesn't stutter or quit. Just smokes and then stops smoking and is fine for the rest of the hour or so that it runs.

So is this because of the break-in oil they put in at the factory/store? Or should I be concerned it might be a prelude to a bigger problem? Maybe the rings aren't seated properly?

I can post a video if needed.

Trying to figure out if I should just go ahead and change the oil and hope that solves it or start a warranty claim with Briggs and Stratton. Not looking forward to that.

Any advice/insight is much appreciated.

Take it back to Lowes and tell them you want another one.

Change the oil & filter .
If you get the same problem with the new oil do as previously advised.
Coming from Lowes you have no idea if or how many times the engine was started before the full compliment of oil was put in.
The engine ship with a tiny amount of oil and the dealer / customer is supposed to fill it before use.
This is why they will let you start some but not others.

I agree...take it back. Sounds like valve seals leaking if only at startup.