10hp Snow King Adjustment Screw

I just put a rebuild kit in my snowblower. Last season, it was loping up and down while ideling. So I bought a kit this year and it was doing it again. I readjusted mixture screw on the side and once I remove the screw driver off the screw, it spins right back in to seated. Then it starts loping. I back the screw out 1-1/2 turns and it runs smooth, remove the screw driver and spins back in.....This seems odd to me.

Any one with some suggestions?

tension spring missing from the adjustment screw allowing the screw to turn freely.

Yup, I dont remember a spring on that screw.

Now I need to source a spring.....