Small Engines (Lawn Mowers, etc.): 18.5 B&S heavy oil smoking, cylinder head bolts, briggs stratton

Question
I have a Briggs & Stratton 18.5 OHV 31P777-0348-E1 that since new has blown heavy smoke if turned hard while in use.  If you go really slow you can get around this.  It normally will not use oil unless you keep making it smoke.  Engine runs fine.  It has started to get worse to the point that if you drive over really rough ground it will trigger the same thing.  People think I'm fogging for insects.  But if I turn slowly and stay on smooth surface it seems fine.  What do you think?

Answer
How new is new?  IT sounds like you could have a valve seal out, a leaky head gasket, (your not overfilled on oil are you) a crankcase vacum leak-check the rubber oring around the dipstick and tube.  If its still under the warranty period, get it back to the dealer ASAP.

Just for the fun of it, check the cylinder head bolts, are they tight?