One other possibility- - - -the carb has a "power valve" that richens the mixture on acceleration. If it sticks, you're running full-rich all the time. There will be a long brass rod in the top of the carb, that works against a spring-loaded valve in the carb body. Pull the top of the carb, and make sure the plunger is free to move. A squirt of spray carb cleaner and a little work will usually free up the plunger. A stuck power valve will really increase the fuel consumption, and foul plugs quickly, even if the carb isn't flooding.
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!