Carb Help!!!

Could try running your mix screws out 3-4 turns and if it runs somewhat better you have a huge vacuum leak if worse you are getting too much fuel.You couls jet the 800 down about 2-3 sizes to see if that clears up the excesive fuel thru it.But keep in mind a 800 cfm will need a bigger jet than a 600 cfm for it to have the right A/F ratio,dont lean it out too much.