This is a classic sign that the internal passages of the carburetor have become plugged with varnish, decreasing the amount of fuel to the engine.
You will need to remove, disassemble and thoroughly clean the carb.
The best way to do that is to disassemble the carb, taking off all non-metal parts, and then soaking it for several hours in a commercial carb solvent. Then spray it clean, making sure to get all holes and passages perfectly clean.
When reassembling, you should always install a carb kit.
hey Hank, dont think its just a carb adjustment
its a 7hp briggs. adjustment screw at base of bowl and at top of carb
Something is restricting the flow of fuel to the engine.
This is very common on a small engine. As gas sits and gets old, it turns to varnish. Varnish is a very hard substance and quickly plugs up a carburetor. Most people mistake this for a mis-adjusted carb and try to open the jets a little more. If the carb is not too bad, this will work temporarily, but it WILL continue to get worse.
The real solution to this is not a carb adjustment - it is a good carb cleaning.