I'm glad you had a happy ending regarding your mower's service. By the way, what model number Lawn Boy do you have?
The two, 6 1/2 HP, 2 stroke, Lawn Boys that I own are powerful enough to cut grass that is over the wheel height without stalling. I am still using from my big stash of old Mobil 1 2T oil in an effort to prolong them.
Anyone looking for a light weight, powerful, mower should hunt around craigslist and ebay for these mowers - while you can still find them.