Small Engines (Lawn Mowers, etc.): Toro Smoker, change spark plug, briggs and stratton

Question
I have a 3-yr old Toro SR-4 Super Recycler walk-behind mower Model 20056 that has given me good service, until now.  I brought it into the authorized sales/service dealer where I purchased it for routine service (blade sharpening, oil change, spark plug, etc.) in the spring.  When mowing for the first time afterward it started to smoke after a half hour of use.  I checked the oil level and it looked dry, to me.  I added oil and finished the lawn.  It kept smoking.  I took it back and complained.  They told me they were sure they filled it and that I had probably overfilled it, causing the smoke.  (They missed the part about it smoking BEFORE I added oil.)  They drained off some oil and sent me packing.  Over subsequent mowings the smoke got worse.  Took it back.  At no cost to me (it's w/in the 5-yr warranty) they replaced the entire Briggs & Stratten motor with a new one.  Or so they tell me.  It still smokes!  Under normal stress the smoke is barely visible, or not visible at all.  But you can smell it.  Under stress it smokes a lot, no longer continuously like before but for short intervals.  Took it back again.  They said they ran the mower and it ran fine.  Must be something I'm doing, according to them.  They said a new motor shouldn't smoke.  Duh.  If these yahoos replaced the motor as they said, what else could be wrong?  Is it time for me to ask Toro for a new mower?

Answer
The chances of Toro giving you a new mower are pretty slim,  Briggs and Stratton has a policy in place to replace engines.  IF the dealer  did in fact put a new engine on it, it should not have the same problem.  I suggest calling Briggs and Stratton at 414-259-5300 and asking for a Technical Service Representative, they will get involved and if need be send a representative from Briggs to your house to inspect this product.  FWIW, try to find out who the DSSM, District Service Manager is for your area... Better yet ask for Doug Doughtery ...National Service Manager he can make this problem go away for you.  He know all the right people to help resolve this.  IT is a Briggs and Stratton Problem, not a Toro Problem.