Cut the lawn more often @ 3-½" and buy a new Gas Powered Mower while you still can! Take good care of it.
Forget all the magic crap. I tried Hi Compression Floor Mats in my Youth. Did not help HP and used more Fuel.
If you watch the many Utube small engine Repair guys like tarryl and Dony boy and B. Pender you will see the gel like substance that forms in the float bowl, emulsion tube etc. Glad you have not had a problem. I don't risk it in Southern Ontario. Perhaps you live in a less humid area. A...