Briggs Runs Too Rich With AirFilter

So I messed around with it this morning. Runs poorly with a dry filter, runs poorly with an oil filter and runs OK without a filter. I left it run for a good while without a filter installed and was able to get it to stumble some. I took the coil off and tested it for resistance, it was in spec. Cleaned the spark plug end as it had corrosion. Still no difference. So back I fear to carb issue. I really think I may just by a new one online just to see if it fixes it. Again it runs fine for about the first 30 seconds even with a filter installed