If the spark plug hasn't been touched in 4500 miles, change it. See if it makes a difference.
I changed mine after 1000 miles because it fowled.
Carquest and O'Reilly's Auto Parts has NGK CR7HSA plugs for about $2.30. Cheap insurance to change it on a regular basis.
Also, put about an ounce of Seafoam in the gas and see if it helps. Otherwise, open the carb and clean all the jets.
so clean the carb? this is happening when i give max throttle from a stop
If it's doing it at max throttle, check that your auto choke is working right. If it's not closing, it could be flooding the carb out.