yup when I inspect the carb on day collection, they did put a screw there, it started from there morning cold start problem. later I re-checked them hoses & mingle a bit until air coming in through the vacuum controller oni, f.i.y I oso do checking on those wires for the controller to see which one do have electricity running, later found out 1 oni have power when I step on the pedal, 1 is on when key is on(did looping for the rad fan through this wires oso) 1 doesn't doesn't have electricity going through so I took that 1 out oso than re-arrange them vacuum hose. maybe this saturday gonna swap the hoses between the 2 controller unit & see what happens. if still persist, maybe swap the controller. if still persist maybe need to look from different view edi.