Set the float level correctly- - - - -you're emptying the float bowl at full throttle and creating a surge. If the fuel pump will flow a pint of gas in 30 seconds at idle speed you have plenty of capacity to support wide open throttle for miles if the float level is OK.

A clogged exhaust system will also cause the symptoms you're experiencing. Take the muffler off and do a test drive.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!