5hp new carb cant find stable air/fuel adjustment

[kinger]

Put a brand new carb and gasket and fuel line on engine .
Started up on 1st pull full choke and 1 push on primer. - set air/fuel screw on bottom of float bowl ran perfect until I put a load on engine then it seems lo load up ( like choke was on ) re-adjust to good run. Then does it again !!

I HAVE NEVER seen this before !!!
What could it possibly be ?

 

[Rivets]

Before anyone can help you we need to know what engine you are talking about. Please supply us with all engine numbers, plus the part number of the new carb and whether you purchased it off the internet or from a dealer. When we know this info, we will be able to offer help. Also, what was the reason for replacing the original carb?