Does adding choke help? I would check the cooling shroud/fins. It may be running hot due to blocked cooling.

Walt Conner

Walt, thanks for the response. I've checked the cooling/fins and everything looks good. I haven't tried the choke yet.

When I mow next time, I'll try this. THANKS

If.......you do check for blockage to the cooling fins, and you DO NOT find anything that would cause overheating, go ahead and run the mower until it begins to run poorly. As soon as you notice the problem coming on, loosen or remove the fuel tank filler cap for a moment and see if that returns the engine to good running order. A clogged vent in the fuel cap can produce the exact symptoms you are having. Loosening or removing the cap will "break the vacuum" that forms in the tank when fuel is consumed with a clogged cap vent. If loosening the cap restores the performance, you need to probe the vent holes in the fuel cap with a suitable piece of stiff wire and/or blow out the obstruction with compressed air.