Sounds like your low end is way too rich. But before your adjust the low end you need to have the high speed set properly. So set your high speed needle so your engine is 400 rpm down from peak at full throttle. Now drop to idle and use your radio trim to get the slowest reliable idle. Idle for 5-10 seconds and go to full throttle. If it quits you are too lean, if it spits out smoke and stubbles to high speed you are too rich. Kill the engine and adjust the low speed needle rich or lean, make 1/2 turn adjustments at first then as you get closer to a good setting make smaller adjustments.

You can usually get a good low speed starting point by setting the throttle to your idle position. Screw the low speed needle in GENTLY until it just touches closed. Blow into the fuel line and slowly open the low speed needle when you hear the air whistling out the carb stop turning the low speed needle.