I have a 1996 Lawn Boy Gold Series push mower that I bought new in 1999 with the F-Series two stroke motor. I run it about 10 hours a year now since I mainly use my landfill-scavenged Toro Super Recycler (2007) with a new in 2023 Briggs 725EXi motor. The Toro gets about 20 hours per year and is my main mower and I highly recommend Briggs & Stratton push mower replacement engines. My rider is a Troy Bilt (MTD) from 2018 that I only use in the fall for leaves and it's down right now for a camshaft. It has a Briggs 17.5 Intek which I don't recommend because I've had problems with the cam decompression and the Nikki carburetor leaking fuel into my motor.