that was of great help to the dude, joew
sound like your not getting the gas where it need's to go
first, change the plug, start with a fresh-e
then check from the fuel tap to the carb if your getting gas flow
next, if you can just clean the carb-do it
other than that, could be the tank not venting
remove the gas cap when she start's to bog see if that helps.
you'll fix it