Richer sounds a bit like a moist/wet fart.
This video might help
https://youtu.be/25UTCijPHjg
My friend had the same problem with a full exhaust. It ran great and his power was smooth. Raising the needle 1 more notch made it ran poor. He ended under raising the needle with a washer. So it was higher but not as high as adjusting it with the clip.
He's running a #40 Pilot Jet
Main Jet is Dyno Jet 115??
Exhaust is Full but don't remember which one.