Have a Briggs 219907-0131E1-050823ZA that is having high speed issue. Just got this and trying to get it cleaned up to resell. Starts fine and will idle at low to medium speed but if you adjust it to high speed it will start sputtering and blowing black smoke like its getting to much gas and just fall on its face and barely run. I took carb apart and blew carb cleaner through all passages and still doing the same. This is a Nikki carb, I have had these carbs have problems on the idle circuit but never on high speed circuit like this. Any suggestions would be greatly appreciated. Thanks