2. Fresh Air.
When you have a cold and cannot breath, you do not perform well, if at all.
Likewise, your small engine needs a breath of fresh air.
A dirty air filter may prevent the engine from running well or even from starting.
Filter Maintenance
Discard paper filters or clean and oil foam filters:
That appear brown or black or full of weeds and dirt.
After 25 hours of use in dusty or heavy use conditions.
Twice a season if it takes longer than an hour to cut your lawn.
In any event, at least once each season.
Cleaning and Oiling a Foam Filter or Foam Filter cover:
Remove the foam and rinse it in a tin with a cup of mineral spirits.
Once clean, gently ring out the mineral spirits.
Add a few drops of 30w (or similar) oil to wet the foam.
Gently ring that out, leaving a light coat in and on the foam.