First, check the exh. for a clogged spark screen and or a clogged exh. port at the cyl. Pull the plug and check condition and gap.
Then make sure the fuel lines are not split/cracked etc. and the filter is flowin.
If the above are OK , then its time to look into the carb, possibly adj the HS needle, if it has one.
" But let me tell you something ,folks: You can't fix stupid!
There's not a pill you can take, there's not a class you can go to. Stupid is forever!"