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.
Buy and install new head bolts. Torque them cold and retorque them next day. Be sure your carb is not running 'lean'. Retard timing slightly and try it.
Well Done Sir. I try to do a good deed and learn something every day. Doesn't always happen but averages out. Check your Oil, clean out your Wallet and buy Wife/GF flowers. Helps your daily odds.
Excellent results with Ultrasonic Rodent devices if you park inside. Signal goes in straight lines outward.. I jamb packed chicken wire in openings of other equipment where possible.
Bob:
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...