All the magnum engine I've ever owned. I just Jb weld the carb to the
engine right off the bat and they all run like champs after that.
It seals it and prevents the carb from rotating loose.

You also want to flush out the needles. Sometime crud gets in there.
Check for loose screw on the head, backplate, ect.
Also try checking the line in the tank. There was a little nik or slit in the line one time.
It started picking up air as the fuel level got lower. It drove me nutz.
I was thinking the engine was crappy becuase it died or over heated after
I put the plane in the air.

For some strange reason I had to backout
the HIGH END (richen)
and lean the LOW end to get idle in.
You would think it's the other way around.
Also remember it's winter time now.
The air is cooler and densor, needs more fuel.