OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines Briggs & Stratton push lawnmower problem

Sounds like a govenor problem.
If so major engine work.
It could be a minor thing like to thin oil.
Check you oil, if it is black and thin change it using a Heavy Duty non-detergent 30 wgt.
Don't put too much oil in the engine this is just as bad.
Most walk behinds with 5 hp or smaller take 16-20 ounces of oil and no more.
If it still hunts after this it is probably govenor problem or possibly a carbureator adjustment problem(or even the external govenor links.)