I have a 3 season old toro weed whacker that wont start. I use true fuel (thanks to a previous really long discussion here) - the plug was pretty bad so i replaced that. Now it makes like a lower noise when I try to start it with the choke off. Flooded? The noise is hard to explain. But it sounds lower and more labored than with the choke on. Thanks for any suggestions.
Usual next step is to try and identify a carb rebuild kit. You may have corrosion, or grit partly plugging one of the passages. I am often impressed what compressed air applied to all the internal passages will do, replacing the gaskets along the way. If 2 cycle, you may have an issue with the reed valves.
Pull the plug and tug a round or two to clear flooding. The plug will be wet with fuel if that’s it. You can also check for compression while doing so. Place a finger over the hole and see if it’s blowing. If it’s not flooding, try adding fuel directly into the carb. I’d use carb cleaner down the throat and see if it fires on that…
Otherwise, audio/ video might help…