Hello I believe I own the same engine so I have an LT 2000 Craftsman it has a 19.5 horsepower OHV engine last summer I was troubleshooting All kinds of various problems with the engine it seemed each day there is a new problem to make a long story short after 6 weeks I took off what was a brand new carburetor and put on another brand new carburetor I made zero adjustments on the second brand new carburetor and everything ran well to this day it still runs perfectly I suggest getting another carburetor. I also can tell you the carburetor that runs perfectly in my machine if interested.
Jim
Jim